Fracture fixation systems

ABSTRACT

Systems for bone fracture repair are disclosed. One system includes a biocompatible putty that may be packed about a bone fracture to provide full loadbearing capabilities within days. The disclosed putties create an osteoconductive scaffold for bone regeneration and degrade over time to harmless 5 resorbable byproducts. Fixation devices for contacting an endosteal wall of an intramedullary (IM) canal of a fractured bone are also disclosed. One such fixation device includes a woven elongated structure fabricated from resorbable polymer filaments. The woven elongated structure has resilient properties that allow the woven 10 structure to be radially compressed and delivered to the IM canal using an insertion tube. When the insertion tube is removed, the woven structure expands towards its relaxed cross-sectional width to engage the endosteal wall. The woven elongated structure is impregnated with a resorbable polymer resin that cures in situ, or in the IM canal.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a national stage filing under 35 U.S.C. 371 ofInternational Application No. PCT/US2009/051715, filed on Jul. 24, 2009,which claims the benefit of the filing date under 35 U.S.C. 119(e)priority to U.S. Provisional Application Ser. No. 61/142,756, filed onJan. 6, 2009, U.S. Provisional Application Ser. No. 61/084,237, filed onJul. 28, 2008, U.S. Provisional Application Ser. No. 61/083,837, filedon Jul. 25, 2008, and G.B. Provisional Application Serial No. 0813659.0,filed on Jul. 25, 2008, the entire contents of which is incorporatedherein by reference. International Application No. PCT/US2009/051715 waspublished under PCT Article 21(2) in English.

BACKGROUND

1. Technical Field

This disclosure relates generally to orthopedic implants and, moreparticularly, to orthopedic implants adapted for fracture repair andmethods for repairing fractures.

2. Description of the Related Art

A variety of systems and devices are conventionally used to treat bonefractures in humans or animals. Bone fractures typically heal naturallyas a result of normal growth or regeneration processes. Treatment ofbone fractures generally includes placing bone fragments into ananatomically correct position and orientation, referred to as“reduction,” and maintaining the fragments in place until healingnaturally occurs, referred to as “fixation.” Accordingly, a primaryobjective in the treatment of bone fractures is the fixation orstabilization of the reduced, fractured bone for the duration of thehealing process.

Conventional systems and devices for treatment of fractures includeexternal fixation means, such as traction, splints, or casts, andinternal fixation means, such as plates, nails, pegs, screws, and otherfixtures. Internal fixation devices are installed on or in the fracturedbone across the fracture site. For example, plates, screws, pegs applycompression forces across a fracture site, thereby aiding in stabilizinga bone fracture across the fracture site. Intramedullary nails areinstalled longitudinally into the intramedullary (IM) canal of afractured bone across the fracture site and provide torsionalstabilization as well as load sharing along the central axis of thebone.

One common problem with internal fixation devices is that theinstallation of such devices is generally dependent on the presence ofsufficient amounts of high quality bone tissue in the vicinity of thefracture. When bone tissue is lost, due to disease, a pathologicalcondition or for other reasons, it may be difficult to install internalfixation devices to stabilize the bone sufficiently for healing. Forexample, persons with thin or fragile bones, such as osteoporosispatients, avascular necrosis patients and patients with metastaticbones, may be particularly prone to difficulties with fixation andhealing of fractures. Unfortunately, these are the very patients thatare most prone to bone fractures. While external fixation devices andmethods are available, external fixation devices can be cumbersome,uncomfortable, limit or prevent ambulation and therefore generally failto satisfy the needs of such patients.

Current fixation devices, both internal and external, also fail to meetthe needs of injured soldiers and other trauma victims. Specifically,approximately thirty percent of all battlefield trauma cases involvebone fractures, typically due to high energy events, such as blasts orgunshots. For example, the combination of comminuted open fractures withlarge bone loss and significant soft tissue loss are common battlefieldtraumas. Such cases, often referred to as “segmental defects,” are verydifficult to treat and typically require multiple surgeries and longhealing/rehabilitation times that can last as long as two years.Amputations in these cases are common.

Current treatment techniques include the use of internal and externalfixation with titanium plates, screws, and rods or IM nails, and theIlizarov distraction method for bone-lengthening. However, currenttechniques suffer from significant deficiencies, some of which arisefrom the mechanical property mismatch between titanium and bone. Thismismatch leads to complications including further fractures, delayedhealing, and a high prevalence of infection. Furthermore, currentlyavailable techniques do not provide the most effective treatment inrepairing large segmental defects, which are generally defined as adefect or missing bone segment that exceeds 2 cm in length or width.Because many currently available fixation devices are not fullyload-bearing, the soldier or patient may be effectively incapacitatedduring the recovery period.

Therefore, in light of the above problems, more effective fixationmethods and devices are urgently needed for the treatment of both commonbone fractures as well as bone fractures considered to be largesegmental defects.

SUMMARY OF THE DISCLOSURE

Various systems for bone fracture repair are disclosed which areapplicable to typical bone fractures without significant bone loss andbone fractures classified as having large or significant segmentaldefects.

One disclosed system may comprise fracture putty in the form of adynamic putty-like material that, when packed in/around a compound bonefracture, may provide full load-bearing capabilities within days. Thedisclosed putties may create an osteoconductive scaffold for boneregeneration. The disclosed putties may also degrade over time toharmless resorbable by-products as normal bone regenerates. Thedisclosed putties may be curable in situ.

The disclosed putties may be made from resorbable polymers which canharden or cure in situ, for example polyurethane, polypropylenefumarate, polycapralactone, etc.

The disclosed putties may include a first or primary filler in the formof biocompatible and osteoconductive particles that can form a scaffoldstructure that bridges healthy bone segments. The first or primaryfiller, preferably in the form of particles, may also provide porosity,bone ingrowth surfaces and enhanced permeability or pore connectivity.One suitable particulate filler material is hydroxyapatite (HA) althoughother suitable filler materials will be apparent to those skilled in theart such as calcium phosphates, orthophosphates, monocalcium phosphates,dicalcium phosphates, tricalcium phosphates, whitlockite, tetracalciumphosphates, amorphous calcium phosphates and combinations thereof.

The particles may comprise degradable polymer (e.g. PU, PLA, PGA, PCL,co-polymers thereof, etc.) or the particles may comprise degradablepolymer containing one or more ceramic fillers. The first fillerparticles may be provided in varying sizes.

In one refinement, the first filler particles have mean diametersranging from about 1 μm to about 15 μm. For example, in one disclosedputty, the first filler has a mean particle size of about 10 μm.

In a refinement, the porosity and compressive properties of thedisclosed putties may be manipulated using additional fillers materialsthat may be HA or another suitable biocompatible material. Suchrefinements include the addition of particles having mean diametersranging from about 400 to about 4000 μm. In certain disclosed putties,the additional filler materials may be provided in one or more sizedistributions. For example, additional filler material is provided insize distributions ranging from about 400 to about 4200 μm, from about400 to about 3200 μm, from about 600 to about 3000 μm, from about 800 toabout 2800 μm, from about 400 to about 2200 μm, from about 800 to about1800 μm, from about 1400 to about 3200 μm, from about 1800 to about 2800μm, etc. The ratio of the particle size distributions can be manipulateddepending upon the compression strength required or the porosityrequired. For example, large segmental defect injuries to load bearingbones will necessitate higher compression strength and possibly reducedporosity. In contrast, large segmental defect injuries to non-loadbearing bones require less compression strength thereby enabling thesurgeon to use the putty with a higher porosity for shorter healingtimes.

In one example, a second filler is added that may have a mean particlediameter ranging from about 400 to about 1800 μm and a third filler thatmay have a mean particle size greater than the mean particle size of thesecond filler and ranging from about 1800 to about 4000 μm.

In a refinement, the resin may be present in an amount ranging fromabout 15 to about 40 wt %, the first filler may be present in an amountranging from about 10 to about 25 wt %, the second filler may be presentin an amount ranging from about 20 to about 40 wt %, and the thirdfiller may be present in an amount ranging from about 15 to about 35 wt%.

In another refinement, the first filler may have a mean particlediameter ranging from about 8 to about 12 μm, the second filler may havea mean particle diameter ranging from about 800 to about 1800 μm and thethird filler may have a mean particle diameter ranging from greater than1800 to about 2800 μm. In a further refinement of this concept, theresin may be present in an amount ranging from about 20 to about 30 wt%, the first filler in an amount ranging from about 10 to about 20 wt %,the second filler in an amount ranging from about 25 to about 35 wt %,the third filler in an amount ranging from about 20 to about 30 wt %.

In another refinement, the first filler is present in a first amount,the second filler is present in a second amount and the third filler ispresent in a third amount. A ratio of the second to third amounts mayrange from about 1:1 to about 1.5:1. In another refinement, a ratio ofthe second and third amounts combined to the first amount may range fromabout 3.5:1 to about 4.5:1

The disclosed putties may also include an additional porogen. In onerefinement, the porogen is mannitol but other biocompatible porogenswill be apparent to those skilled in the art such as crystallinematerials in the form of salts, sugars, etc.

Another disclosed moldable material for orthopedic implantation andreconstruction comprises a resorbable polymer resin present an amountranging from about 20 to about 60 wt %, a first filler having a firstmean particle diameter ranging from about 1 to about 15 μm and presentin an amount ranging from about 10 to about 30 wt %, and mannitol as aporogen and present in an amount ranging from about 30 to about 50 wt %.

The disclosed putties may also include a blowing agent. In onerefinement, the blowing agent is water but other biocompatible blowingagents will be apparent to those skilled in the art.

Fixation devices for contacting an endosteal wall of an intramedullary(IM) canal of a fractured bone are also disclosed. One such fixationdevice comprises a woven elongated structure fabricated from aresorbable polymer filaments. The woven elongated structure may have arelaxed cross-sectional width and a compressed cross-sectional width.The relaxed cross-sectional width may be at least about 50% larger thanthe compressed cross-sectional width. This resilient property allows thewoven structure to be radially compressed, placed in an insertion tubeand delivered to the IM canal using the insertion tube. When theinsertion tube is removed, the woven structure expands towards itsrelaxed cross-sectional width to engage the endosteal wall. The wovenelongated structure may have a closed distal end. The woven elongatedstructure is coated with a resorbable polymer resin that cures in situ,or in the IM canal. The combination of the woven elongated structure andthe cured resin provides a strong internal fixation device.

In a refinement, the woven elongated structure is selected from thegroup consisting of a braided elongated structure, a triaxial braidedelongated structure, a pair of braided elongated structures with onesmaller inner braided elongated structure disposed axially within alarger outer braided elongated structure, a bundle of braided elongatedstructures, a bundle of braided elongated structures disposed axiallywithin an outer braided elongated structure, a braided elongatedstructure with a plurality of cavities extending along a length of thebraided elongated structure, and an elongated structure fabricated fromthe spacer fabric that may be rolled or folded.

For embodiments that employee a triaxial braided elongated structure,the longitudinal fibers may be single or individual fibers, longitudinalfiber bundles or yarns, or the longitudinal fibers may be crimped.

In a refinement, the device may include a retention structure thatsubstantially encloses the woven elongated structure for inhibiting themigration of injected resin out through the woven elongated structureand possibly of the IM canal. The retention structure may be selectedfrom the group consisting of a balloon, a bag, a sheath or othersuitable enclosure. The retention element may be fabricated from aresorbable material, such as a resorbable polymer. In such a refinement,the woven elongated structure may be filled with resin.

In another refinement, the resin may include particulate filler materialas described above. In another refinement, the resin further comprisesreinforcing resorbable fibers. In another refinement, the wovenelongated structure accommodates an elongated structural reinforcingelement.

In a refinement, the woven elongated structure may comprise filamentsselected from the group consisting of polyurethanes, poly-alpha-hydroxyacids, polylactides, polyglycolides, poly-(D,L-lactide-co-glycolide),polyglycolide-co-trimethylenecarbonate, poly-(L-lactide),poly-(L-CO-D,L-lactide), poly-(D,L-lactide), polyglactin acid, acombination, poly-(D-lactide), combinations thereof and copolymersthereof.

In another refinement, the woven elongated structure accommodates aplurality of loose resorbable fibers for mixing with resin injected intothe woven elongated structure.

An assembly for placing a fixation device in contact with an endostealwall of an intramedullary (IM) canal of a fractured bone is alsodisclosed. One disclosed assembly comprises an insertion tube thataccommodates a woven elongated structure as described above. The wovenelongated structure may have a closed distal end and is in compressibleto a cross-section smaller than an inner diameter of the injection tubebut expandable to relaxed cross-section greater than an inner diameterof the injection tube for engaging the endosteal wall of the IM canal.The woven elongated structure accommodates a distal end of an injectiontube for delivering resin to the woven elongated structure.

The woven elongated structure may take the form of any of thealternatives described above, may include a retention element, one ormore reinforcing elements and/or a plurality of loose reinforcingfibers. Further, the use of an insertion tube enables the option ofproviding a woven elongated structure that is pre-wetted with uncuredresin which cures in situ using the assembly described above. In anotherrefinement, the resin is light-curable and can be cured in situ bypassing a light emitting device axially through the woven elongatedstructure after it is placed in the IM canal.

Use of any of the internal fixation devices or systems disclosed hereinmay be combined with one or more external fixation systems, as will beapparent to those skilled in the art.

The disclosed fixation systems and methods may yield one or more of thefollowing benefits: (1) the patient may be more rapidly restored toambulatory function while healing naturally occurs; (2) a singleprocedure may be employed that significantly simplifies orthopedicsurgery; (3) fewer secondary fractures may result from use of thedisclosed systems and methods thereby promoting normal healing and fewerinfections; (4) reduction in recovery/rehabilitation time; (5) potentialtreatment for severe bone loss; (6) potential treatment for jointfractures; (7) reduction in the number of amputations; (8) the fixationsystems are wholly or at least partly resorbable thereby avoiding theneed for a secondary procedure to remove the fixation device after thebone has healed.

There is provided a hardenable and moldable material for orthopedicimplantation and reconstruction, the material comprising: a resorbablepolymer resin; optionally, a first filler having a first mean particlediameter ranging from about 5 to about 15 μm; at least one additionalfiller selected from the group consisting of a second filler having amean particle diameter ranging from about 400 to about 1800 μm and athird filler having a mean particle size greater than the mean particlesize of the second filler and ranging from about 1800 to about 4000 μm,the at least one additional filler increasing a porosity of the materialafter hardening and being present in an amount greater than the firstfiller.

In some embodiments, the resin is present in an amount ranging fromabout 15 to about 40 wt %; the first filler is present in an amountranging from about 10 to about 25 wt %; the additional filler is presentin an amount greater than the first filler and ranging from about 20 toabout 75 wt %.

In some embodiments, the additional filler comprises both second andthird fillers.

In some embodiments, the resin is present in an amount ranging fromabout 15 to about 40 wt %; the first filler is present in an amountranging from about 10 to about 25 wt %; the second filler is present inan amount ranging from about 20 to about 40 wt %; the third filler ispresent in an amount ranging from about 15 to about 35 wt %.

In some embodiments, the first filler is present in a first amount, thesecond filler is present and a second amount and the third filler ispresent in a third amount, and a ratio of the second to third amountsranges from about 1:1 to about 1.5:1.

In some embodiments, a ratio of the second and third amounts combined tothe first amount ranges from about 3.5:1 to about 4.5:1

In some embodiments, the material further includes a porogen comprisingwater soluble crystals.

In some embodiments, the porogen comprises mannitol.

In some embodiments, the material further includes water as a blowingagent.

In some embodiments, the first filler has a mean particle diameterranging from about 8 to about 12 μm, the second filler has a meanparticle diameter ranging from about 800 to about 1800 μm and the thirdfiller has a mean particle diameter ranging from greater than 1800 toabout 2800 μm.

In some embodiments, the resin is present in an amount ranging fromabout 20 to about 30 wt %; the first filler is present in an amountranging from about 10 to about 20 wt %; the second filler is present inan amount ranging from about 25 to about 35 wt %; the third filler ispresent in an amount ranging from about 20 to about 30 wt %.

In some embodiments, the first filler is present in a first amount, thesecond filler is present and a second amount and the third filler ispresent in a third amount, and a ratio of the second to third amountsranges from greater than 1:1 to about 1.5:1.

In some embodiments, a ratio of the second and third amounts to thefirst amount ranges from about 3.5:1 to about 4.5:1

In some embodiments, the material further includes a porogen comprisingwater soluble crystals.

In some embodiments, the first, second and third fillers are selectedfrom the group consisting of hydroxyapatite (HA), calcium phosphates,orthophosphates, monocalcium phosphates, dicalcium phosphates,tricalcium phosphates, whitlockite, tetracalcium phosphates andamorphous calcium phosphates.

In some embodiments, the material further includes water as a blowingagent.

There is provided a moldable, hardenable and porous material fororthopedic implantation and reconstruction, the material comprising: aresorbable polymer resin present in an amount ranging from about 20 toabout 60 wt %; a first filler having a first mean particle diameterranging from about 5 to about 15 μm and present in an amount rangingfrom about 10 to about 30 wt %; and mannitol as a porogen and present inan amount ranging from about 30 to about 50 wt %.

In some embodiments, a second filler having a mean particle diameterranging from about 400 to about 1800 μm; and a third filler having amean particle size greater than the mean particle size of the secondfiller and ranging from about 1800 to about 4000 μm.

In some embodiments, the first filler is selected from the groupconsisting of hydroxyapatite (HA), calcium phosphates, orthophosphates,monocalcium phosphates, dicalcium phosphates, tricalcium phosphates,whitlockite, tetracalcium phosphates and amorphous calcium phosphates.

There is provided a moldable material for orthopedic implantation andreconstruction, the material comprising: a resorbable polymer resinpresent in an amount ranging from about 15 to about 40 wt %; a firstfiller having a first mean particle diameter ranging from about 8 toabout 12 μm and present in an amount ranging from about 10 to about 25wt %; a second filler having a mean particle diameter ranging from about600 to about 1800 μm and present in an amount ranging from about 20 toabout 40 wt %; a third filler having a mean particle size ranging fromgreater than 1800 to about 2800 μm and present in an amount ranging fromabout 15 to about 35 wt %; the second and third fillers increasing aporosity of the material after hardening when present in cumulativeamounts greater than the first filler.

In some embodiments, the first filler is present in a first amount, thesecond filler is present and a second amount and the third filler ispresent in a third amount, and a ratio of the second to third amountsranges from about 1:1 to about 1.5:1.

In some embodiments, a ratio of the second and third amounts combined tothe first amount ranges from about 3.5:1 to about 4.5:1

Other advantages and features will be apparent from the followingdetailed description when read in conjunction with the attacheddrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the disclosed systems and methods,reference should be made to the embodiments illustrated in greaterdetail in the accompanying drawings, wherein:

FIG. 1 is a cross-sectional view of a fracture with a disclosed internalfixation system for fracture repair.

FIG. 2 is a cross-sectional view of a fracture with another disclosedinternal fixation system.

FIG. 3 is a cross-sectional view of a fracture with another disclosedinternal fixation system.

FIG. 4 is a cross-sectional view of a fracture with another disclosedinternal fixation system.

FIG. 5 is a cross-sectional view of a fracture with another disclosedinternal fixation system.

FIG. 6 is a perspective view of the collar used in the system of FIG. 5.

FIG. 7 is a cross-sectional view of a fracture with another disclosedinternal fixation system.

FIG. 8 is an end view of the connector used in the internal fixationsystem of FIG. 7.

FIG. 9 is a cross-sectional view of a fracture with another disclosedinternal fixation system.

FIG. 10 is a cross-sectional view of a fracture with another disclosedinternal fixation system.

FIG. 10A is a cross-sectional view of a fracture with another disclosedinternal fixation system.

FIG. 11 is a cross-sectional view of a fracture with another disclosedinternal fixation system.

FIG. 12 is a cross-sectional view of a fracture with another disclosedsystem.

FIG. 13 is a cross-sectional view of a fracture with another disclosedsystem.

FIG. 14 is a perspective view of an inner ring of the system illustratedin FIG. 13.

FIG. 15 is a top view of an alternative ring for the system of FIG. 13.

FIG. 16 is a cross-sectional view of a fracture with yet anotherdisclosed system.

FIG. 17 is a plan of view an alternative support for the system shown inFIG. 16.

FIG. 18 is a plan view of other alternative support for the system ofFIG. 16.

FIG. 19 is a cross-sectional view of a fracture with another disclosedsystem.

FIG. 20 is a cross-sectional view of a fracture with another disclosedsystem.

FIG. 21 is a cross-sectional view of a fracture with another disclosedsystem.

FIG. 22 schematically illustrates an external fixator attached to abone.

FIG. 23 schematically illustrates the external fixator of FIG. 22attached to a bone with a segmental defect and a disclosed internalfixation system for fracture repair.

FIG. 24 is a schematic cross-section of a fractured bone with anotherdisclosed internal fixation system.

FIG. 25 is a perspective view of a bone used for mechanical testing.

FIG. 26 is a perspective view of a mechanical testing device with thebone of FIG. 26.

FIG. 27 graphically illustrates exemplary results of a mechanical test.

FIG. 28 schematically illustrates an internal fixation or system for usewith an intramedullary nail.

FIG. 29 schematically illustrates an internal fixation system for usewith a bone plate.

FIG. 30 schematically illustrates an internal fixation system utilizingone or more putties disclosed herein.

FIG. 31 is a partial and enlarged view of a disclosed elongated andreinforcing braid structure used with a biocompatible resin and,optionally, one or more of a balloon, a bag, a sleeve, chopped fibers,additional braid structures and/or an additional reinforcing pin or tubeas illustrated below.

FIG. 32 is a partial and enlarged view of a disclosed reinforcing spacerfabric that may be used with a biocompatible resin and, optionally, oneor more of a balloon, a bag, a sleeve, chopped fibers, additional wovenelongated structures and an additional reinforcing pin or tube asillustrated below.

FIG. 32A is a partial and enlarged view of another disclosed reinforcingspacer fabric similar to FIG. 32, with thicker longitudinal fibers orfiber bundles and spacings between groups of vertical fibers.

FIG. 33 is a photograph illustrating a topological texture induced in abraid surface as a result of argon etching.

FIG. 34 is an end view of an elongated braided structure with aplurality of longitudinal reinforcing fiber bundles.

FIG. 35 graphically illustrates the effect of a number of longitudinalfibers filaments in longitudinal fiber bundles on loadbearing propertiesof elongated braid structures equipped with longitudinal fiber bundles.

FIG. 36 is a side to sectional view of an insertion assembly for placinga disclosed reinforcing device in an IM canal amount wherein thereinforcing device comprises a braid or spacer fabric as illustrated inFIGS. 31-32A respectively.

FIG. 37 is an insertion tube for use with the insertion assembly of FIG.36.

FIG. 38 is a schematic sectional view of a fractured bone, IM canal andinsertion port that has been previously drilled through the outercortical and endosteal wall structures of the fractured bone.

FIG. 39 is a schematic sectional view of the bone illustrated in FIG. 38with the insertion tube of FIG. 37 disposed therein.

FIG. 40 is a schematic sectional view of the assembly, insertion tubeand bone of FIGS. 36-39, particularly illustrating the insertion of theassembly through the insertion tube.

FIG. 41 is a schematic sectional view of the assembly, insertion tubeand bone of FIGS. 36-40, particularly illustrating the placement of theassembly across the fracture site.

FIG. 42 is a schematic sectional view of the assembly and bone of FIGS.36 and 38-41, after the insertion tube of FIG. 37 has been removed andthe braid or spacer fabric has been allowed to expand.

FIG. 43 is a schematic sectional view of the assembly and bone of FIGS.36 and 38-42, particularly illustrating the injection of resin into thebraid or spacer fabric and optional balloon, bag or sleeve.

FIG. 44 is a schematic and sectional view of a braid or spacer fabric,optional balloon, bag or sleeve, and resin disposed across a fracturesite, whereby if an optional balloon, bag or sleeve is utilized, excessballoon, bag or sleeve material is cut at the insertion port through thecortical wall.

FIG. 45 is a sectional view of one disclosed assembly for use with theprocedure illustrated in FIGS. 38-44.

FIG. 46 is a sectional view of another disclosed assembly for use withthe procedure illustrated in FIGS. 38-44.

FIG. 47 is a sectional view of yet another disclosed assembly for usewith the procedure illustrated in FIGS. 38-44.

FIG. 48 is a sectional view of another disclosed assembly for use withthe procedure illustrated in FIGS. 38-44.

FIG. 49 is an end view of a dual braid system with a smaller elongatedbraid disposed axially within a larger elongated braid.

FIG. 50 is an end view illustrating the use of a bundle of elongatedbraids, in this example, five braids.

FIG. 51 is an end view illustrating the use of a bundle of elongatedbraids disposed axially within a larger elongated braid.

FIG. 52 is an end view of a braid with four separate cavities thatextend axially along the braid.

FIG. 53 illustrates the braid with three cavities that extend axiallyalong the braid.

FIG. 54 illustrates a braid with six peripheral cavities and a centralaxial cavity that extend along the braid.

It should be understood that the drawings are not necessarily to scaleand that the disclosed embodiments are sometimes illustrateddiagrammatically and in partial views. In certain instances, detailswhich are not necessary for an understanding of the disclosed systemsand methods or which render other details difficult to perceive may havebeen omitted. It should be understood, of course, that this disclosureis not limited to the particular embodiments illustrated herein.

DETAILED DESCRIPTION OF THE PRESENTLY PREFERRED EMBODIMENTS

The disclosed systems and methods are also advantageously used intreatment of bone fractures associated with disease, pathologicalconditions or injury.

Treatment of Bone Fractures

Healing of bone fractures generally occurs, at least to some degree,naturally in humans or animals as a result of formation of new bonetissue in a fractured bone. New bone formation, which is sometimestermed “ossification” or bone “in-growth,” naturally occurs due to theactivity of bone cells, such as osteoblasts and osteoclasts andeventually results in closing of a fracture site with newly formedtissue. In order for the bone tissue to grow such that a fractured boneheals into its pre-fracture form and restores its function, the bonepieces or fragments have to be located in their appropriate naturalphysical position and orientation, a process referred to as “reduction.”Further, the bone fragments must be maintained in said position andorientation for the duration of the healing, referred to as “fixation.”Treatment of fractures is generally aimed at providing the bestconditions for a bone to heal and preventing movement of a bone or itsfragments in order to prevent or lessen damage to bone, cartilage orsoft tissues. Systems disclosed herein are designed to assist in bothreduction and fixation and enhance bone in-growth across a fracture siteby providing biocompatible materials that form a scaffold across afracture site.

Resorbable Materials

Disclosed methods or devices may comprise or utilize one or moreresorbable, bioerodible, or degradable material for fixation devices.Upon installation of a fixation device comprising such material, gradualresorption of the material takes place, thereby making space availablefor bone ingrowth, which can be advantageous over the use ofnon-resorbable metal materials for fixation devices. The term“biodegradable” may be used interchangeably with the terms“bioabsorbable”, “bioresorbable”, “resorbable”, “degradable”,“erodible”, or “bioerodible”, and these terms are used to characterizematerials that gradually disintegrate after implantation into a human oran animal.

Biodegradable materials used may be beneficial for promotion of tissueformation, with properties such as porosity and degradation chosen toencourage tissue growth and vascularization, if appropriate, within thematerial. Degradation rate may be coupled to the rate of bone tissueformation so that neither the load-bearing capabilities of the tissue,nor tissue regeneration are compromised. Accordingly, degradation rateof biodegradable materials may be timed to ensure adequate time forgrowth of bone tissue into a void, space, or cavity between a bone and ajoint implant. The resorbable material may be at least partiallyresorbed over a predetermined period of time. The degradation time maybe chosen depending on a particular application and can range from a fewweeks to a few years or more. As with all implanted materials,biodegradable materials may be sterilizable to prevent infection.Sterilization may or may not substantially interfere with thebioactivity of the material, alter its chemical composition or affectits biocompatibility or degradation properties.

The resorbable materials may include, but are not limited to, polymericmaterials, such as polyurethane, poly-alpha-hydroxy acids, polylactideand polyglycolide, including their copolymers,poly-(D,L-lactide-co-glycolide) andpolyglycolide-co-trimethylenecarbonate; stereopolymers, such aspoly-(L-lactide) or poly-Lactic acid (PLA), poly-(L-CO-D,L-lactide) andpoly-(D,L-lactide), polyglactin acid (PGA), a combination thereof(PLA/PGA) or any derivative, combination, composite, or variationthereof, poly-(D,L-lactide-co-glycolide) (PDLLA-co-PGA),poly-(L-lactide) (PLLA), poly-(D-lactide) (PDLA),polyglycolide-co-trimethylenecarbonate, (PGA-co-TMC),poly-(L-CO-D,L-lactide), poly-(D,L-lactide), (PDLLA). The use of slowdegrading and highly crystalline polymers, such as poly-(L-lactide) andpoly(L-CO-D,L-lactide) stereocopolymers with a low D,L amount, amorphouspolymers, such as poly-(L-CO-D,L-lactide) stereocopolymers with a highD,L amount of poly-(D,L-lactide), or fast-degrading copolymers, such aspoly-(D,L-lactide-co-glycolide) orpolyglycolide-co-trimethylenecarbonate, is envisioned and falls withinthe scope of this disclosure. The use of injectable or crosslinkablepolymers, including, but not limited to, photopolymerizable andchemically polymerizable polymers and polymers that harden in situ, isalso encompassed by this disclosure, including but not limited to theuse of polymers of sebacic acid (SA), alone, or copolymers of SA and1,3-bis(p-carboxyphenoxy)propane (CPP), or1,6-bis(p-carboxyphenoxy)hexane (CPH), or poly(propylene fumarate)(PPF). Resorbable materials are not limited to the foregoing and mayalso include any fully or partially degradable or erodible in a bodychemical composition, including but not limited to carbohydrates andderivatives thereof, such as such as cellulose or hyaluronic acid. Amodification of polymeric materials to adjust their structural,mechanical or chemical properties, or facilitate biological responses intissues is envisioned and falls within the scope of this disclosure. Theresorbable material may include a two phase polymer system wherein onephase degrades faster than another to allow for adequate strength andbone in-growth. The system may be a non-miscible blend. An example ofthe two phase polymer system is PDLA in combination with polyurethane.

Hardenable Void Fillers—Putties and Resins

Disclosed methods or devices may comprise or utilize one or more ofhardenable resins that are biocompatible and at least partiallyresorbable. A term “hardenable” as used herein means that the materialis able to change consistency, harden, stiffen, crosslink, cure andbecome firm, stable, or settled. Both putties and resins may beinjectable before they cure. The disclosed putties generally includeresin, with additional filler materials to make the putty more viscousand moldable. The disclosed putties are used alone or in combinationwith additional fixation devices for the repair of segmental defects. Incontrast, disclosed resins are primarily used in the IM canal incombination with one or more reinforcing and/or containment devices.

Certain disclosed polyurethane resins are two component materialavailable from PolyNovo Biomaterials Pty. Ltd. of Australia(http://www.polynovo.com/). One particularly suitable polyurethane resinis made from a hydroxyl functional material (R—OH) that is reacted witha polyisocyanate (R—NCO). The setting time of the resin is controlledthrough the addition of one or more catalysts to the reaction mixture.The isocyanate may be ethyl-lysine diisocyanate (ELDI) and the hydroxylmay be pentaerythritol. The polyurethane may include an ester bond,which allows for hydrolyzed degradation to take place.

The PolyNovo polyurethane resins and alternative resins are described inthe following U.S. Patent Application Publications and PCT Application:(1) 2005/0197422; (2) 2005/0238683; (3) 2006/0051394; and WO2009/043099, each of which is herein incorporated by reference.

With the addition of fillers, the polyurethane resin can form a puttywhich is moldable by hand. Other additives such as porogens and blowingagents are used to create porosity.

In addition to polyurethanes, the disclosed putties and resins, thedisclosed putties may be made from resorbable polymers which can hardenor cure in situ, for example polyurethane, polypropylene fumarate,polycapralactone,etc.

Alternatively, the resin, or putty made therefrom, may be an injectableand/or moldable, biocompatible calcium phosphate material that sets insitu, such as NORIAN® (Norian Corporation of 1302 Wrights Lane East,West Chester, Pa., USA).

The resin may also comprise a biocompatible epoxy resin. The most commoncommercially available epoxy resin is Diglycidyl Ether of Bisphenol-A(DGEBA) which is the reaction product of Bisphenol A andEpichlorohydrin.

The resins and putties made from the resins may be customized. Inparticular, properties of a putty or resin are designed, selected ormodified so that the material possesses properties suitable or desirablefor stabilization of a fracture when injected into the bone cavity.Examples of some of the material's properties that can be customizedinclude, but are not limited to: porosity, pore connectivity,permeability, compression strength, Young's modulus, bending modulus,shear modulus, torsional modulus, yield strength, ultimate strength, orPoisson's ratio. A putty or resin may be further stabilized to contain aradio opaque material for x-ray visualization in order to assess orimprove positioning intra-operatively, and monitor an implant duringfollow up visits.

The resin may comprise a suitable degradable ceramic cement suchcomprising any one or more of, brushite, calcium sulphate and calciumphosphate.

The resins may comprise degradable glass ionomers. These resins can beproduced by combining acid functionalized polymers with ion leachingglasses such as a degradable polyacrylic acid-co-caprolatone copolymersor a polyamino acid combined with degradable glasses which liberatedivalent and trivalent ionic species such as calcium, magnium, zinc,aluminium, iron, copper etc.

Degradable polymeric based cements may also comprise unsaturated lowmolecular weight polymers, such as fumerates or branched or telechelicmacromers based on degradable polyester, polyamide, polyurethane,polycarbonate, etc. One example is low molecular weightpolylactide-glycolide containing unsaturated acrylate groups which canbe activated in situ by the addition of a chemical activating agent(e.g., a peroxide or azo compound) and/or the addition of energy (e.g.,electromagnetic (light), heat, ultrasound, etc.).

Exemplary Putties

Hydroxyapatite (HA) is an ideal filler for use with a polymer resin toform a moldable putty because of its low cost, radiopaque properties andosteoconductive properties. Although the examples below include HA(hydroxyapatite) as the fillers, those having ordinary skill in the artwould understand that other forms of calcium phosphate may be used. Asexamples, other apatites, calcium phosphates, orthophosphates,monocalcium phosphates, dicalcium phosphates, tricalcium phosphates,whitlockite, tetracalcium phosphates, amorphous calcium phosphates maybe substituted for HA. The filler particles may also be composites,e.g., particles of polymer and calcium phosphate materials such as HA.

In the examples that follow, a porous and hand moldable putty isprovided from a polyurethane resin and an HA filler. However, resinsother than polyurethane may be employed as discussed above. The puttiesform a porous scaffold across a fracture site that cures in situ at bodytemperatures. By varying the amount of filler and optionally utilizingone or more porogens and/or blowing agents, the properties of the puttycan be customized to a particular application or injury.

The particle size range of HA can range from about 5 μm to about 4000μm. However, in the examples that follow, the HA was sieved to particlesizes from about 10 μm to about 2800 μm. The HA content of the resultingputties ranged from about 15 wt % to about 80 wt %. Using differentparticle sizes and amounts of HA, or various size distributions of HA,it was found that the porosity and compressive properties of the puttiescan be manipulated for the injury being treated.

For example, increasing the amount of the 10 μm particle size HA (i.e.,the “first” filler) will increase the compressive strength of the puttyand will eventually lower the porosity of the putty. To provide abalance between compressive strength and porosity, a combination ofsmall particle or 10 μm particle HA and large particle or 800- and 2800μm HA (i.e., as “second” and possibly “third” fillers) may be utilized.

Other samples use a blowing agent as well as HA filler in theformulation. A blowing agent will aid in the creation of open cellporosity by rapidly off gassing in the resin to form bubbles. Theblowing agent used was H₂O, which off gasses carbon dioxide. However,other blowing agents will be apparent to those skilled in the art. Thisand the combination of adhesive particles also yield hand moldable puttythat is porous.

Lastly, 10 μm size HA was used as filler with a porogen in the form ofmannitol, from SPI Pharma Inc. of Wilmington Del.(http://www.spipharma.com/). The mannitol not only acts as a porogen butalso appears to reinforce the compressive strength of the putty until itdegrades leaving void spaces in the putty. The mannitol porogen used hasa sieve size ranging from about 170 μm to 1900 μm. These voids areconnected resulting in open celled porosity because of the contactbetween the mannitol particles.

The addition of porogens and the employment of particle sizemanipulation can provide homogenous porosity values. Fast dissolvingporogens include, but are not limited to mannitol, calcium sulfate andother salts and sugars. In contrast, a discrete amount of putty or resinmay be mixed with loose particles of a solid material, such as calciumphosphates, in order to stick the loose particles together but not fillall the spaces between them, which results in a porous putty. The solidparticles may be of the same material, such as fast or slow resorbingmaterials or may include biologically active or non-active materials.

Once the resin is mixed, the HA particles, optional mannitol andoptional water are added and blended with the resin mixture at roomtemperature. The resin will typically cure or set at body temperature.

TABLE 1 Weight Percent Formulation of Samples 170 μm-1.9 mm 10 μm 0.8mm- mannitol H₂O HA 2.8 mm HA Ratio of 0.8- particles (blowing SampleResin particles particles 1.8/1.8-2.8 mm (porogen) agent) No. (wt %) (wt%) (wt %) HA particles (wt %) (wt %) I 29.4 0 70.6 13:11 0 0 II 25.0 1560.0 13:11 0 0 III 23.3 14 62.8 16:11 0 0 IV 45.5 54.5 0 n/a 0 0 V 24.714.8 59.3 13:11 0 1.2 VI 43.5 17.4 0 n/a 39.1 0

TABLE 2 Mechanical Results Compression Porosity Connectivity Sample No.(MPa; Mean) (%) (%) I 12 34.3 99 II 12 15 95 III 6 31 99 IV 20 24 97 V 333 99 VI 19 n/a n/a

As shown above, Samples I-VI provided various values for compressivestrength, which were generated using an aqueous compression test method.The method includes conditioning the sample for 24 hours in a phosphatebuffered saline (PBS) solution at 37° C. (body temperature) beforecompression testing. The samples were dimensioned by casting the samplesin a PTFE split mold (a right cylinder with the length at twice thediameter (24 mm×12 mm)) for 15 minutes at room temperature, inaccordance with ASTM D695. Next, the samples were removed from the moldand conditioned at 37° C. for two hours then placed in the PBS solution.

After being conditioned for 24 hours in solution, the samples weretested using the MTS 150 screw machine. The test speed of the screwmachine was at 1 mm/min, which is in compliance with ASTM D695. A 5 KNload cell was used to measure stress. Most of the compression testsamples were greater than or equal to cancellous bone, which is about 10MPa according to McCalden et al., JBJS, 1997, vol. 79, pp. 421-427.Three repetitive tests were conducted in the results averaged and listedin Table 2.

Samples I-VI were also tested for porosity and pore connectivity using aμCT machine. By using this machine, cross sectional images can be takento measure cell formation. See Table 2 for porosity results.

Unlike other resorbable resins, the above samples exhibit a porositythat is created by using varying filler particles of varying sizes,porogens and/or blowing agent. Also the samples remained moldable byhand with the properties of being drillable and radiopaque after cure.

The disclosed putties may include one or more antibiotics, one or moreantimicrobials for fighting infection. The disclosed putties may alsoinclude osteoconductive additive such as one or more bone morphogeneticproteins (BMPs). The resin of the disclosed putties may includecomponents that are not degradable or resorbable such as reinforcingfibers. The disclosed resins may also be ultraviolet (UV) light curableor cross-link curable. In addition to polyurethane, other in situhardening or curing materials can be used, e.g., polypropylene fumerate.

By using various amounts and particle sizes of filler, e.g., HA,drillable, moldable and osteoconductive putties are disclosed that canbe remodeled by bone. The different size filler particles along withvarying amounts of filler also result in improved compressive strength.The disclosed putties provide the surgeon more control of the pore size.The disclosed putties may be hand deliverable by the surgeon and do notrequire special injection devices.

The putty may incorporate a calcium phosphate mixture formed by firstsoaking conventional hydroxyapatite (HA) powder (such as a commerciallyavailable HA powder having an average particle size of about 45 to about125 μm) in a silver nitrate-containing and/or silver fluoride-containingaqueous or organic solution for a period of time. The aqueous or organicsolution may comprise both silver fluoride and silver nitrate. Betatricalcium phosphate may be substituted for HA or HA may be combinedwith beta tricalcium phosphate. The calcium phosphate mixture includesabout 0.1 percent to about ten percent by weight of silver. The calciumphosphate mixture may include about 0.5 percent to about three percentby weight of silver. One or more of carbonate, fluoride, silicon,magnesium, strontium, vanadium, lithium, copper, and zinc may be addedto the calcium phosphate mixture.

The disclosed fracture putties may be curable in vivo and may bedesigned to closely match the mechanical (stress/strain—in tension,compression, bending, and torsion) and structural properties of naturalbone. In general, the disclosed fracture putties provide initialfracture fixation, followed by full load-bearing capability for patientambulation and create an optimal mechanical environment in the form of ascaffold structure which promotes natural bone regrowth or ingrowth,including within large gaps between bone segments. The disclosedfracture putties may be intrinsically non-toxic and non-antigenic, andmay degrade into harmless resorbable by-products, and/or be resorbed byosteoclasts, the body's bone-dissolving cells, as bone regenerates,thereby transferring load-bearing to bone over time. The disclosedfracture putties may be compatible with, and infusible by, existingosteoinductive bone pastes, bone morphogenetic proteins, growth factors,antibiotics, antimicrobials, non-degradable components, ultraviolet (UV)curable cross linkers, etc.

In general, the procedure for fracture treatment using a disclosed puttyincludes the following steps: (1) reduce fracture; (2) make an entrypoint, which may be collinear with the axis of the bone or oblique tothe axis of the bone; and (3) apply putty in the IM canal across thefracture to achieve adequate fixation on either side of the fracture.The procedure may also include preparing the canal. This may beaccomplished with a standard reamer or a reamer with an expandablecutting head. The procedure may include inserting an additional deviceinto the intramedullary canal and/or across the fracture as described inFIGS. 1-3, 5, 7, 9-13, 16, 19-21, 23-24 and 28-30.

The putty or resin may contain a reinforcing element, such as fibers ora particulate. Fibrous reinforcing materials include, but are notlimited to, ceramic fibers or whiskers, polymeric fibers and metalfibers, for example, fibers made from magnesium and its alloys aredegradable. Polymer materials may include, but are not limited to,homopolymers and co-polymers of PET, PP, PE, Nylon, PEEK, PLA, and PGA.Particulate reinforcing material may be in the shape of plates or rods.Examples include clays, micas, alumina, hydroxyapatite, calciumcarbonate, calcium phosphates, and zirconia.

Some of the disclosed putties have a strength of at least 200 MPa, whileothers have a strength of at least 500 MPa.

It is particularly advantageous if the void filler bonds to the exposedbone within the defect. The void filler may also comprise an allogenicor autologous bone graft material. The void filler may also comprise aparticulate or granular bone substitute material such as JAX™ (Smith &Nephew, Inc). Depending on the type of void filler used, additionalstrength properties may be conferred up the system.

Alternatively, one or more rods, pins or tubes of a stiff material maybe placed into the intramedullary canal, which are then anchored inplace by injection or insertion of the putty or resin. Examples of thestiff materials include metals, ceramics and polymers. With polymers thestiffness could be enhanced by preparing orientated rods, such as by diedrawing. Another example is the use of composite materials for the rods,such as a PEEK/carbon fiber composite or degradable PLLA fibercomposites.

Further, as noted below, a braided, woven or knitted sleeve may beplaced into the intramedullary canal and impregnated with the putty orresin. The sleeve may be made from a resorbable or non-resorbablematerial. The sleeve may include a radio-opaque marker. The sleeve maybe compressed radially or stretched axially via instrumentation forinsertion, such that when inserted and released, it can expand toconform to the dimensions of the intramedullary canal. The sleeve may bemade from resorbable fibers, such as PDLA.

Also, as noted below, a bag or balloon may be used to fill theintramedullary canal and filled with the putty or resin. When the deviceis pressurized and expands it engages into the endosteal wall to fixatethe device via friction. An adhesive may be applied to the outer surfaceof the bag so that it will adhere to the endosteal wall after placement,thereby enhancing fixation. The bag/balloon device may have someporosity to allow the putty or resin to perfuse/leach to enable it toadhere to the endosteal wall. There may be a section in the centralregion of the bag/balloon that contains no porosity to prevent leakageof the putty or resin into the fracture gap. The bag or balloon mayalternatively have reinforcing ribs or rods attached to either its inneror outer surface.

A bag or balloon may also be used to fill the intramedullary canal andfilled with a pressurized liquid and then sealed. This has the advantagethat the liquid can be removed at a later date to facilitate removal ofthe device. Alternatively, the liquid may reversibly solidify, such aspolycaprolactone or a thermo-reversable gel.

FIGS. 1-29

Referring to the accompanying drawings in which like reference numbersindicate like elements, FIG. 1 illustrates a bone 100 with fracture 102and a system 10 for fracture repair. The system 10 includes a hardenableputty 12 and a fixator 14 inserted into the intramedullary canal. Theputty 12 may be made of a polyurethane material having embedded ceramicparticles, chopped fibers and/or HA particles. Further, in FIG. 1, thefixator 14 may be a braided sleeve made from poly-L-lactide (PLLA)fibers and impregnated with polyurethane resin. The sleeve may beimpregnated in vivo. The fixator 14 may also include axial channels or acannulation.

In FIG. 1, the fixator 14 is illustrated as engaging the endosteal orcortical wall of the bone 100. Alternatively, the fixator 14 may besized to allow for blood flow between the endosteal wall and the fixator14. The fixator 14 may be pinned or fastened on each side of thefracture 102 to connect the bone segments. For example, resorbablescrews may be used to fasten the fixator 14 to the bone 100.

In another embodiment, the putty 12 is replaced by a resorbable metalspacer formed as a monolith with a central axial bore that accommodatesthe fixator 14. Additional resin or putty may be used to fill any cracksor voids.

FIG. 2 illustrates the bone 100 having the fracture 102 and a system 110for fracture repair. The system 110 includes a resorbable and hardenableputty 112, a fixator 114, and a hardenable tube 116. In FIG. 2, thefixator 114 may be a braided sleeve (see also FIG. 31) made from PLLAfibers or a spacer fabric (see also FIGS. 32 and 32A) made from PLLA andimpregnated with the resorbable and hardenable putty 112, or ahardenable and resorbable polyurethane resin. The sleeve may beimpregnated in vivo. The tube 116 may be made from a shape memorymaterial, such as a shape memory polymer. The tube 116 may beconstructed and arranged such that the tube 116 has a first size beforeimplantation but changes to achieve a second size after implantationbased upon the shape memory effect. Alternatively, the fixator 114 mayinclude axial channels or a cannulation.

FIG. 3 illustrates the bone 100 having the fracture 102 and a system 210for fracture repair. The system 210 includes a resorbable putty 212, afixator 214, and a wrapping 216. Wrapping 216 is made from a meshmaterial impregnated with a putty or resin, such as polyurethane resin.The wrapping 216 may be impregnated in vivo. The fixator 214 is madefrom a resorbable material, such as a shape memory polymer. The fixator214 may include axial channels or a cannulation.

In FIG. 3, the fixator 214 may comprise a degradable scaffold section214 a disposed between degradable internal splint sections 214 b. Thedegradable scaffold 214 a may be more porous and may be provided in theforms of injectable gels, resins, or preformed structures. The wrapping216 may be in the form of a degradable tissue guided scaffold andoptional incorporation of an active material such as an antibiotic,steroid, etc. The internal splint sections 214 b may be made ofresorbable fibers impregnated with an in-situ settable resin. The tissueguided (TGS) scaffold 216 may be placed round the defect direct cellgrowth and to act as a retaining mechanism for soft gels, resins, looseparticulates or cements. The TGS 216 may be porous to encourage tissueingrowth. In one embodiment, the TGS 216 is a body temperature activatedshape memory split tube which activates and tightens around the bone100. The TSG 216 may have pores in the range of about 35 μm to trapmacrophages which then cause cells to liberate cell signaling moleculesand resulting tissue repair. The gel, putty or paste 212 can be composedof gelling materials such as PLAGA granules, hylaronic acid, lightcurable materials such as polylactide-based macromers, collogen,gelatin, chitosan sponge, calcium sulphate, in situ setting ceramiccement, etc.

FIG. 4 illustrates the bone 100 having the fracture 102 and a system310. The system 310 includes a hardenable putty 312 and a plurality ofceramic channels or chopped fibers 318. The hardenable putty 312 may bepolyurethane resin and HA particles or another suitable filler. If thefracture 102 is sufficiently small, the putty or resin 312 may be merelypolyurethane resin. As examples, if channels 318 are employed, thechannels 318 may be tubes, plates, or cones. The putty 312 and theceramic channels or chopped fibers 318 may be mixed together and placedin the fracture 102. For example, the putty 312 and the chopped fibersor ceramic channels 318 may be shaped into a cylinder. Once the puttycylinder 312 is placed in the fracture 102, the fracture 102 andadjacent area may be wrapped to add strength and hold the putty 312 inplace. As examples, the fracture 102 may be wrapped with a resorbablematerial, a putty or resin, a woven resorbable material, or a wovenmaterial impregnated with a foam or non-foam putty or resin.

FIGS. 5-6 illustrate the bone 100 having the fracture 102 and a system410. The system 410 may include a balloon 412, a collar pair 414, and atleast one band 416. The balloon 412, the collar pair 414, and at leastone band 416 all may be made from a resorbable material. The balloon 412expands in multiple directions. Thus, in FIG. 5, the balloon 412 expandsinto the intramedullary canal and into the segmental defect. Portions ofthe balloon 412 may include a gripper 420 for gripping the endostealwall or other portions of bone. The balloon 412 may be filled with aputty or resin, such as a polyurethane resin. As best seen in FIG. 6,the collar pair 414 may include structural ribs 418. The balloon 412 mayinclude axial channels or a cannulation to allow for blood flow.

Alternatively, the balloon 412 may be replaced with putty or resin, andthe collars 414 replaced with tubular structures that are held in placeby the bands or clamps 416.

FIG. 7 illustrates the bone 100 having the fracture 102 and a system 500for fracture repair. The system 500 includes a collar 510 and a fixator512. The collar 510 is made from a porous shape memory material. Thefixator 512 may be a pre-formed part and may be impregnated with a puttyor resin such as a polyurethane resin. As best seen in FIG. 8, thecollar 510 is generally cylindrical and includes peripheral passages514, a second face 516, and tabs 518. The passages 514 may becylindrical and allow for bone in-growth. The tabs 518 engage the bonesurface to substantially prevent rotation of the bone segments. Thefixator 512 may also include axial channels or a cannulation.

FIG. 9 illustrates the bone 100 having the fracture 102 and a system 600for fracture repair. The system 600 includes a first putty or resin 610,a second putty 612, and a third putty 614. The first, second and thirdputties 610, 612, 614 may be hardenable and/or resorbable and theporosity and compressive strength may be varied as disclosed above,depending upon the particular injury and patient condition.

FIG. 10 illustrates the bone 100 having the fracture 102 and a system700 for fracture repair. The system 700 includes a fitting 710. Thefitting 710 may be T-shaped or Y-shaped. The fitting 710 may be formedof a single component or from two members spliced together. The fitting710 may be filled with a putty or resin. The fitting 710 may be made ofa braided material. A resorbable putty 712 may be packed around thefitting 710. The resorbable putty 712 may be porous. After the fitting710 is placed into the intramedullary canal, a portion of the fitting710 may be snipped or broken off. The fitting 710 may be made of aresorbable material. FIG. 10A illustrates another fitting 710 a witharrow-shaped or barbed ends 710 b. The ends 710 b may be threaded. Thefitting 710 a may be made of a resorbable material.

FIG. 11 illustrates the bone 100 having the fracture 102 and a system800 for fracture repair. The system 800 includes a reinforced resin orputty 810 for mechanical strength and a hardenable and resorbable putty812. The putty 812 may be porous for bone ingrowth. The dimensions “d”and “l” may be controlled depending upon the size of the fracture site.The reinforced putty or resin 810 may include axial channels or acannulation.

FIG. 12 illustrates the bone 100 having the fracture 102 and a system900 for fracture repair. The system 900 includes a fixator 910 made of aresin and a braided mesh wrap 912 impregnated with the resin. The resinmay be applied as a foam. The braided mesh may provide a porousscaffold. The fixator 910 may include axial channels or a cannulation.

In any of the above-examples, the endosteal surface of theintramedullary canal may be rifled or spirally cut to improve torsionalstrength. In any of the above examples, the system may include a guidedtissue regeneration membrane. The guided tissue regeneration membranemay be placed between soft tissue and the fracture repair device. Asexamples, the membrane may be placed between soft tissue and the puttyor resin, between the soft tissue and the resorbable material, betweenthe soft tissue and the wrap, between the fixator and the soft tissue,or the membrane may be used in place of the wrap. The membrane preventssoft tissue from growing into the fracture repair device but does allowfor bone in-growth. As an example, guided tissue regeneration membranemay be BIO-GIDE® Resorbable Bilayer Membrane. BIO-GIDE is a registeredtrademark of Osteomedical Ltd. of Parliament Street 14-16, Dublin,Ireland. The guided tissue regeneration membrane may be coated withsilver or silver salt for antimicrobial purposes.

FIG. 13 illustrates another system 1100 for fracture repair. The system1100 includes a fixator 1110, an optional support 1112 (see also FIG.14), optional sutures 1112 a and optional rod-like supports 1112 b. Thefixator 1110 may be made of a solid material, a porous material, abraided material, or some combination thereof. In one embodiment, thefixator 1110 is a press-fit rod made from resilient plastic. The system1100 may also include a hardenable and resorbable putty 1114. Theoptional support 1112 may be generally cylindrical, oval, C-shaped orU-shaped. The support 1112 may be made from a porous material, a highstrength resorbable material, or magnesium. The support 1112 may be madefrom a shape memory foam. The support 1112 may be placed within thefracture gap or segmental defect to provide structural support betweenthe bone ends. Several supports 1112 of different sizes and/or lengthmay be contained within a kit, and a health care provider may select theappropriate size and/or length for the particular fracture gap orsegmental defect from the kit. Another option is to use rod-likesupports 1112 b.

Still referring to FIG. 13, the fixator 1110 is typically placed in theintramedullary canal as shown. The fixator 1110 may be impregnated witha resin, such as a polyurethane resin or one of the alternativesdescribed above. The support 1112 then may be placed between the bonesegments and around the fixator 1110. In some embodiments, the putty orresin 1114 may be packed around the support 1112. In other embodiments,no supports 1112, 1112 b are utilized and the putty or resin is packedaround fixator 1110. In still other embodiments, resorbable sutures 1112a may be wrapped around the exterior of the bone to minimize rotation ofthe bone segments. The sutures 1112 a may be employed with or withoutsupports 1112, 1112 b.

FIG. 14 illustrates the support 1112 of the system 1100 of FIG. 13.Typically, the support 1112 is C-shaped and includes protrusions 1116along its inner wall. The protrusions 1116 may be used to frictionallyor mechanically engage the fixator 1110. Alternatively, the protrusionsmay be used to provide a space between the support 1112 and the fixator1110. The protrusions 1116 may be randomly placed or placed in a patternand may be omitted entirely. If used, the protrusions 1116 may have anyshape. As examples, the protrusions 1116 may be cylindrical, square,triangular, or conical. In FIG. 14, the protrusions 1116 arecylindrical. The protrusions 1116 may have any length. For example, eachprotrusion 1116 may have a length in the range from about 0.1 mm toabout 5 mm, and more preferably from about 0.5 mm to about 3 mm. In thedepicted embodiment, each protrusion has a length of about 1.5 mm.

FIG. 15 illustrates an alternative to the support 1112 of FIGS. 13-14.In FIG. 15, the support 1112 has exterior spaces or gaps 1111 and radialprotrusions 1113. The spaces 1111 may receive the putty or resin 1114.

FIG. 16 illustrates another system for fracture repair 1200. The system1200 includes a fixator 1210 and a plurality of supports 1212. Thefixator 1210 may be made of a solid material, a porous material, abraided material, or some combination thereof. The supports 1212 may bespaced about the fracture gap or segmental defect. Any number ofsupports 1212 may be used. As an example, from about two to about eightsupports 1212 may be used within the fracture gap or segmental defect.In FIG. 16, three supports 1212 are used (one of the supports is hiddenby the fixator), each being about 120 degrees apart. The supports 1212may be made from a porous material, a high strength resorbable material,such as a magnesium alloy. The supports 1212 may be made from a shapememory foam. The supports 1212 may be placed within the fracture gap orsegmental defect to provide structural support between the bone ends.Several supports 1212 of different thickness and/or length may becontained within a kit, and a health care provider may select theappropriate thickness and/or length for the particular fracture gap orsegmental defect from the kit. The system 1200 of FIG. 16 may alsoinclude a putty or resin (not shown) placed in-between and around thesupports 1212.

In one method, the fixator 1210 is placed in the IM canal. The fixator1210 may then be impregnated resin. The supports 1212 then may be placedbetween the bone segments and around the fixator 1210. One of thedisclosed putties may be packed around the support 1212.

FIGS. 17 and 18 illustrate alternatives to the supports 1212 illustratedin FIG. 16. In FIG. 17, the support 1212′ is H-shaped. In FIG. 18, thesupport 1212″ is I-shaped.

FIG. 19 illustrates another system 1300 for fracture repair. The system1300 includes a fixator 1310. The fixator 1310 may be made of a solidmaterial, a porous material, a braided material, or some combinationthereof. As shown in FIG. 19, the fixator 1310 has intramedullary canalportion and a support portion 1312. The fixator 1310 may be unitary orintegrally formed. The system 1300 may also include a disclosed putty1314. The support portion 1312 may be generally cylindrical, oval,square, hexagonal, or some other shape. As also shown in FIG. 19, thesupport portion 1312 extends radially beyond the intramedullary canal toprovide support to the bone segments. The support portion 1312 may bemade from the same material as the fixator 1310 or a different material.As examples, the support portion 1312 may be made from a porousmaterial, a high strength resorbable material, magnesium, or a shapememory material. Several fixators 1310 with support portions 1312 ofdifferent sizes and/or length may be contained within a kit, and ahealth care provider may select the appropriate size and/or length forthe particular fracture gap or segmental defect from the kit.

Still referring to FIG. 19, in one disclosed method, the fixator 1310 isplaced in the intramedullary canal and fixator 1310 is impregnated withresin. The putty 1314 may then be packed around the support portion1312.

FIG. 20 illustrates yet another system 1400 for fracture repair. Thesystem 1400 includes a fixator 1410 and at least two supports 1412. Thefixator 1410 may be made of a solid material, a porous material, abraided material, or some combination thereof. In the depictedembodiment, there are two supports 1412, each one placed adjacent a bonesegment. The system 1400 may also include a putty or resin 1414. Thesupports 1412 may be generally cylindrical, oval, C-shaped or U-shaped.As examples, the supports 1412 may be made from a metal, anon-resorbable material, a porous material, a high strength resorbablematerial, magnesium, or a shape memory material. The support 1412 may beplaced within the fracture gap or segmental defect to provide structuralsupport between the bone ends. The supports 1412 may be adapted tofrictionally or mechanically engage the fixator 1410. The supports 1412may be fastened to the fixator 1410 through the use of a fastener (notshown).

The supports 1412 may also include protrusions (not shown) along thefixator contacting surface, similar to the support 1112 of the FIG. 14.The supports 1412 of FIG. 20 may be arranged with a space in-between orstacked upon one another to substantially fill the fracture gap orsegmental defect. While in FIG. 20 the supports 1412 appear parallel toone another, those having ordinary skill in the art would understandthat the supports 1412 are more likely to be angled relative to oneanother with the particular angle dependent upon the size and shape ofthe particular fracture gap or segmental defect. Several supports 1412of different size and/or thickness may be contained within a kit, and ahealth care provider may select the appropriate size and/or thicknessfor the particular fracture gap or segmental defect from the kit.

Still referring to FIG. 20, in one disclosed method, the fixator 1410 isplaced in the IM canal. The fixator 1410 is impregnated with the puttyor resin. The supports 1412 then may be placed between the bone segmentsand around the fixator 1410. The putty 1414 may be packed around thesupport 1412.

FIG. 21 illustrates another system 1500 for fracture repair. The system1500 includes a fixator 1510 and at least two pin supports 1512. Thefixator 1510 may be made of a solid material, a porous material, abraided material, or some combination thereof. As shown in FIG. 21, twopin supports 1512 are employed, each one placed adjacent a bone segment.However, those having ordinary skill in the art would understand thatany number of pin supports 1512 may be used. The system 1500 may alsoinclude a putty or resin 1514. The pin supports 1512 may be generallycylindrical, square, hexagonal, or triangular. The pin supports 1512 maybe provided in the shape of a fastener, such as a screw. As examples,the supports 1512 may be made from a metal, a non-resorbable material, aporous material, a high strength resorbable material, magnesium, or ashape memory material. The supports 1512 may be placed partially into orentirely through the fixator 1510. In one embodiment, four pin supports1512 are employed in the form of two substantially diametrically opposedpairs, each pin support 1512 extending only partially into the fixator.While in FIG. 21, the pin supports 1512 appear parallel to one another,those having ordinary skill in the art would understand that the pinsupports 1512 are more likely to be angled relative to one another withthe particular angle dependent upon the size and shape of the particularfracture gap or segmental defect. Several supports 1512 of differentthickness and/or length may be contained within a kit, and a health careprovider may select the appropriate thickness and/or length for theparticular fracture gap or segmental defect from the kit.

In one disclosed method, the fixator 1510 is placed in theintramedullary canal. The fixator 1510 may then impregnated with aresin. The supports 1512 may then be placed between the bone segmentsand through the fixator 1510. The putty 1514 may then be packed aroundthe supports 1512.

FIGS. 22-27 illustrate the use of the system for fracture repair.Although the system is illustrated in use on a sheep femur, the systemis applicable to any mammalian bone. Referring now to FIG. 22, the bone100 is first reamed. The intramedullary canal is reamed up to about 11.5mm using a reaming tool. As best seen in FIG. 23, an external fixationdevice 1000 is then used to fixate the bone (to preserve bone alignment)while a segmental defect 1010 of about 25 mm is made in generally themid-diaphyseal region using a hack saw. The segmental section 1010 ofbone 100 is then removed and all remaining marrow and fat is removedfrom the intramedullary canal using cotton swabs (not shown). A braidedsleeve or tube of space or material 1012 is then inserted into theintramedullary canal until the canal is completely filled and thesegmental defect 1010 is bridged.

The sleeve 1012 may be a braid of PLLA fibers having an outside diameterof about 7 mm, and the sleeve 1012 may be previously heat-set to expandthe sleeve to about 12 mm when deployed. The term “heat-set” refers to aprocess that sets the braid to a new diameter via a thermal treatment.What is significant is that the braid has a first diameter (in this case12 mm) and recovers to the first diameter after stretching to achieve asecond diameter (in this case 7 mm).

Referring now to FIG. 24, a small section of resorbable mesh 1016 isthen impregnated with a foaming formulation of polyurethane material andwrapped around the segmental defect section 1010 of the bone 100. Thebone 100 is then placed in an oven at 37 degrees C. for approximatelytwo hours to allow the polyurethane foam to fully set. The bone 100 isthen removed from the oven and allowed to sit for about 8 to about 16hours.

In about twenty-four hours, an injectable, non-foaming formulation ofpolyurethane material is injected into the braided sleeve 1012 in thebone's intramedullary canal. The braided sleeve 1012 may include axialchannels or a cannulation to allow for blood flow. The polyurethaneresin is filled to the top of the bone 100, and small leaks at thesegmental defect section 1010 may be closed off to prevent loss of resinmaterial. The bone 100 may be allowed to set for about 1 to about 4days, e.g., for about two days, to allow full curing prior to pottingfor subsequent mechanical testing. Potting involves using a two-partPMMA dental bone cement mixed in a ratio of two-parts powder to one-partliquid. After potting, the bone 100 is allowed to sit for about 8 toabout 16 hours.

As best seen in FIGS. 25-26, mechanical testing employs a bearing rollerplate fixture 1020 that allows loading of a femoral head of the bone100. The fixture is set up such that only the femoral head is in contactwith the fixture during displacement of a crosshead 1022. A simplecompression method is used with a strain endpoint of 100%. Load isapplied at a speed of about 5 mm/min. until failure of the construct.

FIG. 27 illustrates one example of the results of mechanical testing. Inthe graph shown in FIG. 27, the maximum load achieved is approximately30-50% of normal weight bearing. During testing, failure appears to bein bending only and not achieved by torque failure. The shape of theintramedullary canal when filled with the polyurethane-impregnatedbraided sleeve 1012 may prevent rotation of the relative bone segments.The failure appears to be ductile, which is significant as it avoids acatastrophic failure. Ductile failure is preferred because if a deviceis overloaded, it will bend rather than shatter.

Any of embodiments disclosed herein may be used to augment external orother internal fixation devices. FIG. 23 illustrates an external fixatoraugmented with the system 1010; FIGS. 28 and 29 illustrate two moreexamples of augmentation.

FIG. 28 schematically illustrates a fracture repair system for use withan intramedullary nail 1610. The system 1600 may includes an optionalfixator 1630 or simply be packed with void filler 1650 in the form ofresin or putty. If used, the fixator 1630 may be fabricated from abraided sleeve but other materials could equally be used. The system1600 may also include a support 1640 and/or a putty or resin 1650. Theintramedullary nail 1610 may be placed in the intramedullary canal andheld in place with one or more fasteners 1620, which may be screws. Theintramedullary nail 1610 may be made of any biocompatible material,including, but not limited to, stainless steel, titanium, andcarbon-reinforced PEEK. The system 1600 may be used with theintramedullary nail 1610 to augment fixation.

FIG. 29 schematically illustrates a fracture repair system for use withan external fixator such as a bone plate 1710. See also the externalfixator 1000 of FIG. 23. The system 1700 includes may include aninternal fixator 1730. The system 1700 may also include a support 1740and/or a putty or resin 1750. The bone plate 1710 may be placed on thebone and held in place with one or more fasteners 1740. The bone plate1710 may be made of any biocompatible material, including, but notlimited to, stainless steel, titanium, and carbon-reinforced PEEK. Thesystem 1700 may be used with the bone plate 1710 to augment fixation.

In other embodiments, the fracture repair system may use an externalfixator to augment the internal support and putty/resin combination.Typical external fixators include Ilizarov frames, hexapod frames, andbar frames.

FIGS. 30-54

Additional embodiments that make use of the polyurethane resins andpolyurethane-based putties disclosed above in combination with braidedsleeves, spacer fabrics, balloons, bags, sleeves, chopped fibers andadditional structural reinforcing elements, will be discussed below inconnection with FIGS. 30-48.

Turning to FIG. 30, a bone 100 is shown with a fracture 102. It will beassumed that the fracture 102 is greater than 2 cm wide and is thereforeconsidered to be a large segmental defect. After cavities 1801 areformed in the two bone segments, the cavities 1801 and IM canal may bepacked with a putty 1802 with a high degree of strength upon curing.Because bone ingrowth in the IM canal is not important and structuralintegrity during the healing process is paramount, the putty 1802 maycomprise a polyurethane resin with a relatively high 10 μm HA particlecontent and relatively low porosity such as sample IV of Tables 1 and 2above.

After the first putty 1802 is in place, a second putty 1803 may bemolded in the annular area of cortical bone loss. Because cortical boneingrowth is paramount for the annular area in which the second putty1803 is placed, the second putty 1803 should be porous upon curing likesamples II, III or VI. Obviously, the exact formulas for the putties1802, 1803 may be varied as will be apparent to those skilled in theart. Further, the putties 1802 and 1803 may be combined with any one ormore of the supporting structural elements described above in connectionwith FIGS. 1-29 or below in connection with FIGS. 31-45.

Turning to FIG. 31, an exemplary braided structure 1805 is disclosed.The braided structure 1805 includes a plurality of bundles 1806 witheach bundle including a plurality of filaments 1807. The braidedstructure 1805 is also characterized by the braid angle θ, which is theangle between the bundles 1806 and the long axis 1808 of the braidedstructure 1805. The braid diameter, or the diameter of the finishedbraided elongated structure 1805 after heat setting and in a relaxedstate, is also a relevant physical property. The “locked-out” diameterof a braided elongated structure 1805 is also a relevant physicalproperty. The locked-out diameter of a braided elongated structure 1805is defined as the diameter of the braided structure 1805 when thestructure 1805 is fully stretched along its long axis 1808. Thelocked-out diameter of a braided structure 1805 is related to the numberof braiding heads used to weave the elongated braided structure 1805,the number of filaments 1807 in each bundle 1806 and the braiding angleθ. If the number of braiding heads and the number of filaments 1807 ineach bundle 1806 is constant, the diameter of the locked-out braid 1805will decrease as the braiding angle θ decreases. As the ratio of thebraid diameter (after heat setting, relaxed state) to the locked-outdiameter increases, the braid becomes more open in the relaxed state,i.e. the openings between the bundles increase in size and the elongatedbraided structure 1805 filled with resin is more prone to leakagebetween the bundles 1806.

Effect of Braiding Parameters on Braid Performance in Fracture FixationDevice

A range of biaxial braids were produced from PLLA monofilaments, 100 μmin diameter. Properties of the elongated braided structures aresummarized in Table 3 below.

TABLE 3 Braid Properties Locked- Diameter of Diameter of Braid outmandrel mandrel length (mm) Filaments braid braid used for heat (locked-Braid Braid Braiding per diameter manufactured setting out angle θ refno. heads bundle (mm) on (mm) (mm) state) (°) 66/01 16 32 4.43 6.25 6.2522.8 11 66/02 16 32 4.36 6.25 6.25 31.2 8 66/03 16 32 4.51 6.25 6.2526.0 9.8 67/01 16 19 3.60 6.25 6.25 9.6 20.6 67/02 16 19 3.43 6.25 6.2520.0 9.7 67/03 16 19 3.54 6.25 6.25 34.8 5.8 68/01 16 27 4.41 6.25 6.2511.2 21.5 68/02 16 27 4.35 6.25 6.25 22.5 10.9 68/03 16 27 4.18 6.256.25 31.5 7.6

The elongated braided structures were produced in sleeve format on a16-head machine (Pickmaster, JB Hyde & Co). Each head was threaded upwith 100 μm PLLA filament ends. The fiber bundles (or yarns) weretwisted at a rate of 20 turns per meter to help maintain theirintegrity. The bundles were then braided over a fixed diameter mandrelusing a bias weave. In this configuration, the continuous yarns crossedover and under each other to form a continuous spiral pattern with eightbundles traveling in one direction and the remaining eight bundles in anopposite direction.

A series of braids were produced with varying braid length, defined asthe length of braid per 360 degrees revolution of each yarn around thebraid. The braid length was measured in a locked-out state (i.e., fullystretched in the axial directions) as the braid came off the machine.The woven sleeves were heat-set over the same diameter mandrel byimmersion in hot water at 90 degrees C. for about 10 seconds.

The elongated braided structures were then tested for bending strengthby placing the elongated braided structures in a PTFE oven with acylindrical cavity 7 mm in diameter and 100 mm long. The 100 mm lengthof braid was inserted into the cavity, which was then filled with adegradable polyurethane resin (PolyNovo Pty. Ltd.) and allowed to cureat 37 degrees C. for 72 hours. The samples were removed from the ovenand left to cure at 37 degrees C. for another 24 hours. The samples werethen removed from the oven and tested in 3 point bend with a supportspan of 70 mm and a cross head speed of 3.4 mm/min. The flexural modulusfrom the test for the different braids is shown in the table below.

TABLE 4 Effect of Braid Length and Angle on Flexural Modulus Braid BraidFlexural Braid ref. length angle modulus/ no. (mm) θ (°) (GPa) 66/0122.8 11 2.63 66/02 31.2 8 2.81 66/03 26.0 9.8 2.97 67/01 9.6 20.6 2.1967/02 20.0 9.7 2.24 67/03 34.8 5.8 2.49 68/01 11.2 21.5 2.26 68/02 22.510.9 2.37 68/03 31.5 7.6 2.72

From Table 4, it can be observed that as the braid length increases, theflexural modulus increases. This behavior was attributed to higher braidlengths resulting in reduced braid angles θ, i.e., the angle between thedirection of the fibers in a bundle and the longitudinal axis of thebraid. The resulting improved alignment between the fibers and the braidresults in a greater proportion of the fibers' properties contributingto the overall strength of the composite material. However, it is alsoobserved that, as the braid length increases, the springiness orrecovery force of the elongated braided structures decreases, which isundesirable. Further, the elongated braided structures with longer braidlengths were also observed to larger interstices in the relaxed stateand were therefore more prone to allowing leakage of the resin throughthe walls of the elongated braided structures. Both of theseobservations appear to indicate that (1) elongated braid structures withhigh braid lengths have lower recovery forces and are therefore lesslikely to self expand and conform to the endosteal wall that (2) suchelongated braid structures will allow significant leakage of resin pastthe braid and may therefore may need a retention means for inhibitingmigration of resin such as a balloon, bag or sleeve as discussed belowin connection with FIGS. 36-48.

Braids with increased numbers of filaments in each bundle were found tobe harder to compress and would require a larger entry hole into thebone. Alternatively, as the braid length increases, the braid becomeseasier to compress. As a result, elongated braid structures with braidangles θ greater than about 8 degrees are suitable for most fracturefixation applications. Ideally the braid angle θ ranges from about 8degrees to about 20 degrees, more preferably from about 8 degrees toabout 12 degrees.

Surface Treatment of Braids of Braid/Polyurethane Resin CompositeStructures

Surface treatments of braids were conducted to determine the effect onthe properties of the composite structure (i.e., braid and resin).Sections of the braid number 66/03 were treated as follows with theresults being tabulated in Table 5. A control braid washed inisoproponal for a minimum of 2 hrs and air dried. For the air plasmatreatment, the braid treated with air plasma for 5 minutes at a pressureof 1.2×10⁻¹ bar, at a reflected power of 5 W. For the extended argonplasma treatment, the braid was exposed for 20 minutes in a 60 degreesC. chamber temperature, 2×10⁻¹ pressure and a reflected power of 20 W.For the NaOH etch, the braid was immersed in 4 M NaOH solution for 2hours and then air dried. For the allyl alcohol plasma, the braid wastreated at a pressure of 200 mtorr allyl alcohol and a reflected powerof 20 W with a treatment cycle comprising 2 minutes of continuous waveplasma followed by 15 minutes of pulsed plasma with a duty cycle of 1 ms(on)/5 ms (on & off). The flexural properties of the composites madefrom the above surface-treated braids are given in the Table 5 below.The polyurethane resin contained 20 wt % HA with an average particlesize below 10 μm (Plasma Biotal, UK) as a filler.

TABLE 5 Effects of Surface Treatment on Elongated Braid StructuresFlexural strength/ Flexural modulus/ Braid treatment (MPa) (GPa)Control-no treatment 97.8 2.97 Air Plasma 105.3 2.93 Argon Plasma 116.43.13 NaOH etch (4M solution) 104.0 2.89 Allyl Alcohol plasma 118.7 3.20

As shown in SEM image of FIG. 33, the argon plasma treatment creates amicro-texture on the surface of the PLLA fibers. Without being bound toany particular theory, it is believed that the microtexture shown inFIG. 33 will improve the mechanical interlocking between the fibers inthe braid and the cured polyurethane resin and hence improve themechanical properties of the final composite structure which comprisesan elongated braid saturated with polyurethane or another suitableresin, which has been cured.

Braids with Longitudinal Fibers

The mechanical performance of the elongated braided structures can befurther improved by the incorporation of longitudinal fibers.Specifically, the cross-sectional view of FIG. 34 shows an elongatedbraid 1815 with braid bundles 1807 and the longitudinal fiber bundles1816. The additional longitudinal fibers 1816 are aligned with the axis1808 of the braid 1815 and significantly improve the bending strength ofthe final composite material, which is the primary loading conditionimposed on fracture fixation devices. Such braids 1815 are also referredto as triaxial braids.

For example, triaxial braids 1815 were made which had an approximaterelaxed external diameter of 3 mm. The elongated braided structures 1815were manufactured to a nominal external diameter of 3 mm with eightbundles 1816 of longitudinal fibers per braid. Triaxial braids 1850 withbundles 1860 of longitudinal fibers of two, five and eight fibers weremade and tested.

Testing was done by inserting the elongated braided structures into aplastic rod of 70 mm length, with a cut half way to simulate a fracture.As an example, the plastic rod could be made of Delrin®. Delrin® is aregistered trademark of E.I. Du Pont De Nemours and Company ofWilmington, Del. The rod has an internal channel through the sectionwith a 3 mm diameter. After placement of the braid, a polyurethane resinwas used to fill the canal and left to cure at 37 degrees C. The sampleswere then tested using a cantilever test method. One side of the plasticrod was firmly clamped, and the plastic rod on the opposite side of thesimulated fracture was loaded at a distance of 25 mm from the fractureat a rate of 10 mm/min. A chamfer at an angle of 45 degrees C. was cuton the lower side of the plastic rod each side of the fracture toprevent the two pieces of plastic impinging on each other during thetest.

The corresponding moment v. extension curves 1820, 1821, 1822 for thetwo longitudinal filaments per bundle 1816 sample, five longitudinalfilaments per bundle 1816 sample and eight longitudinal filaments perbundle 1816 sample respectively are graphically presented in FIG. 35. Itcan be seen that as the number of longitudinal fibers increases from twolongitudinal filaments per longitudinal bundle 1816 (see the plot line1820) to eight longitudinal filaments per longitudinal filament bundle1816 (see the plot line 1822), the load required (y-axis) to deform thesample to a given extension (x-axis) increases.

Alternatively, the ability of triaxial braids 1815 to be compressed andreturn to the heat-set diameter can be improved by using crimped fibersas the longitudinal reinforcement. Crimped longitudinal fibers can beused individually, i.e., as a single fiber, or can be combined intobundles like those shown at 1816 in FIG. 34.

Further, the braids for the fracture fixation devices may be made frombraids or cords. For example, PLLA filaments (˜100 μm diameter) could bebraided into a cord to produce a cord with a 2 mm diameter. These cordscould then be braided into a biaxial or triaxial braided sleeve suitablefor bones with large IM canals. The advantage braided cord or braidedbraid designs is excellent recovery properties. In contrast, largebraids made from PLLA filaments alone may not have sufficient recoveryproperties.

Shaped Tip to Facilitate Insertion of the Elongated Braid or SpacerFabric

Turning to FIGS. 36 and 38, a shaped, tapered or pointed distal end 1830of the elongated braided structure 1805 improves the ease in which abraid 1805 can be inserted into a bone 100 through a narrow injectionopening or port 1831 or the ease in which a braid 1805 and assembly 1835can be inserted through the opening 1831. The assembly 1835 shown inFIG. 36 may include a balloon 1836 (or alternatively, bag or sleeve), aninjection tube 1837, chopped fibers (not shown) and structuralreinforcing elements (also not shown). Ideally, the end 1830 of theelongated braided structure 1805 is shaped into a point as shown in FIG.36. The pointed end 1830 can be formed by melting the end of theelongated braided structure 1805 (or spacer fabric structure 1810) in aconical mold (not shown) to produce a pointed tip 1830. If the elongatedbraided structure 1805 is to be used in a segmental defect (FIG. 30)then a pointed end 1830 can be formed at both ends of the elongatedbraided structure 1805 to improve the insertion into the bone IM cavityof each piece of bone. Other shapes for the tip 1830, where thecross-sectional area of the tip 1830 is less than the cross-sectionalarea of the elongated braided structure 1805 will also improve theinsertion ability. Examples include a rounded tip, a flat ribbon liketip with rounded or sharp point, or a curved tip to aid in non-axialentries. Other tip designs are too numerous to mention here as will beapparent to those skilled in the art.

It is also possible to include a radiopaque material or marker into theshaped tip 1830 to allow visualization of the distal end 1830 of theelongated braided structure 1805 during insertion. This would allow thesurgeon to ensure the elongated braided structure 1805 is inserted pastthe fracture site 102 to an optimal position before the resin ininserted and allowed to cure. For example the shaped tip 1830 could bemade by melting some PLLA (or other degradable polymer) containing aradiopaque filler (e.g., hydroxyapatite) around the end 1830 of theelongated braided structure 1805 during the shaping operation.

Ideal Filler Level for Resin

To allow the samples to be radiopaque, about 20 wt % hydroxyapatite (HA)was mixed with the polyurethane resin. A range of particle sizes wereinvestigated, particle size analysis data is given in the table below.Particle characterization was carried out using a Beckman Coulter LS 13320 Series Laser Diffraction Size Analyzer with Tornado Dry PowderSystem. All HA was oven dried, sintered and milled to form angularshaped particles (no spray dried) and supplied by Plasma Biotal, UK.

TABLE 6 Effect of HA Mean Particle Variation on Braid/Resin CompositeStructures HA Mean (μm) d₁₀ d₅₀ d₉₀ Powder 1 9.982 6.128 11.55 16.74Powder 2 107.5 68.78 135.5 192.5 Powder 3 281.3 167.3 316.1 524.8Mean is the volume mean diameter, d₁₀ is the diameter size wherein 10%of the sample has a smaller diameter; d₅₀ is the diameter size wherein50% of the sample has a smaller diameter; and d₉₀ is the diameter sizewherein 90% of the sample has a smaller diameter.

It was found that if the HA particles were too large then they settledunder gravity in the resin before it cured. To best accommodate theviscosity of the polyurethane resin, a powder with an average size ofaround 10 μm was found to be ideal. To determine the ideal filler level,a series of samples were made with Powder 1 (Table 6) at differentfiller levels as shown in Table 7. Braid ref. no. 67/02 (Table 4) wasused for each sample. The samples were made by placing the elongatedbraided structures in a PTFE mold with a cylindrical cavity 7 mm indiameter and 100 mm long. The 100 mm length of braid was inserted intothe cavity, which was then filled with a degradable polyurethane resin(PolyNovo Pty Ltd) containing the fillers and allowed to cure in an ovenat 37 degrees C. for 72 hours. The samples were then removed from themold and left in the oven to cure at 37 degrees C. for a further 24hours. The samples were then removed from the oven and tested formechanical strength in three-point bend with a support span of 70 mm anda cross head speed of 3.4 mm/min. The flexural modulus from the test forthe different braids is shown in the Table 7.

TABLE 7 Effect of HA Content on Braid/Resin Composite Structures FillerLevel Peak Flex Flex Modulus Strain to Failure (% w/w) Strength (MPa)(GPa) (%) 20 65.6 2.3 No failure observed to 21% strain 25 57.5 2.2 Nofailure observed to 21% strain 30 64.9 2.6 12.6 35 69.4 3.1 9.5 40 63.83.5 5.5

It can be seen that, as the wt % of fillers increases, in general, theflexural modulus of the samples increases and that the strain to failuredecreases. Based on the results obtained for mechanical properties andradiopacity, a HA filler with a particle size of around 10 μm and at alevel between 20 and 35 wt % is satisfactory, with a level of 30 wt %being more satisfactory. Higher or lower HA levels would be acceptable,depending on the application.

As illustrated in connection with FIGS. 36-48, the elongated braidedstructures 1805 or spacer fabric could also be contained in a balloon1836, bag or sleeve. Balloons 1836, bags or sleeves may eliminate orreduce resin leakage past the elongated braided structure 1805 or spacerfabric and into the fracture site, also known as extravasation. Use ofcrimped fibers as longitudinal components in a triaxial braid 1815 (FIG.34) may also provide improved performance. Use of braids 1805 made morebundles and fibers produce braids 1805 with a tighter weave therebyreducing leakage of resin through the elongated braided structure 1805.

As shown below, a braided elongated structure 1805 may be used toprovide reinforcement for an in situ curable intramedullary fixationdevice. The elongated braided structure 1805 may be inserted into the IMcanal of the bone 100, followed by an in situ curable resin, e.g.polyurethane resin, which will penetrate the elongated braided structure1805 and harden. After the resin has cured, the combination of the resinand braid 1805 forms a fiber reinforced composite structure.

Similar to a braided elongated structure 1805, a structure made fromspacer fabric structures 1810, 1810 a as shown in FIGS. 32-32A may beemployed. The spacer fabric structures 1810, 1810 a also readily absorbresin and form a fiber reinforced composite material similar to thebraided structure 1805 of FIG. 31. Once formed as an elongated roll,fold or elongated structure, the spacer fabric structures 1810, 1810 acan be compressed and subsequently expand to the generally cylindrical,but irregular shape of an IM canal. For example, the spacer fabricstructures 1810, 1810 a that have a relaxed cross-sectional width ofabout 8 mm can be compressed to fit inside an insertion tube with aninner diameter of about 3.9 mm, leaving room for an axial injection tubehaving an OD of about 2 mm.

In FIGS. 32-32A, the spacer fabrics 1810, 1810 a include top and bottompanels 1814 a-1814 b and 1814 c-1814 d respectively. In FIG. 32 themiddle section 1813 includes an essentially uniform distribution offibers extending between the top and bottom panels 1814 a, 1814 b. InFIG. 32A, groups of vertical fibers 1813 a are spaced apart. As oneexample, for a piece of spacer fabric 1810 a that is about 14 mm wideand about 8 mm thick, the groups of fibers 1813 a may have widths ofabout 3 mm with spacings of about 2 mm between groups 1813 a. Of course,these dimensions can vary greatly and will depend on the width,thickness and desired compressibility and expandability properties ofthe spacer fabric.

In FIG. 32A, the spacer fabric 1810 a includes longitudinal fibers 1811or longitudinal fiber bundles having diameters greater than thetransverse fibers 1812. For a spacer fabric 1810 a that is about 14 mmwide, 8 mm thick, the longitudinal fibers 1811 may have diameters ofabout 100 μm while the transverse fibers 1812 may have smallerdiameters, for example about 20 μm. Multiple longitudinal fiber bundlesor yarns may be used instead of single longitudinal fibers 1811. Thevertical fibers 1813 a may also have larger diameters of about 100 μm.One disclosed spacer fabric is fabricated from PLLA but other resorbablepolymer fibers discussed above may be used as will be apparent to thoseskilled in the art.

Methods and instruments for introducing fixation devices in the IM canalof a fractured bone are illustrated in FIGS. 36-48. Turning first toFIG. 36, an insertion assembly 1835 comprises an injection tube 1837with a proximal end 1838 connected to an injection port 1839. Theinjection tube 1837 also includes a distal end 1840 disposed axiallywithin the elongated braided structure 1805 (or spacer fabric structure1810). In the embodiment shown in FIG. 36, the elongated braidedstructure 1805 is contained within a balloon 1836 which may also be abag, sleeve or other suitable retention element. The injection tube 1837passes through a hemostasis valve 1841 that includes a filter side port1842 which contains fluid but allows air or gases to release, and a port1843 through which the injection tube 1837 passes. An insertion tube orcatheter 1850 is shown in FIG. 37 with a flared proximal end 1851 and anarrow distal or insertion end 1852.

Turning to FIG. 38, an injection port 1831 is formed in the corticalwall of the fractured bone 100 by drilling or other means and the IMcanal is reamed or otherwise prepared using methods known to thoseskilled in the art. In FIG. 39, the insertion tube 1850 is insertedthrough the port 1831 so that its distal end 1852 extends past thefracture 102. As shown in FIG. 40, the assembly 1835 is inserted throughthe proximal end 1851 of the insertion tube 1850. As shown in FIG. 41,the assembly 1835 is pushed downward through the insertion tube 1850until the elongated braided structure 1805 straddles either side of thefracture 102.

Once the position shown in FIG. 41 is reached, the insertion tube 1850can be withdrawn through the opening as indicated in FIG. 42. As shownin FIG. 43, the elongated braided structure 1805 and balloon 1836 can befilled with resin using the injector 1860. During the injection processillustrated in FIG. 43, the injection tube 1837 can be retractedproximally from the position shown in FIG. 42 to the position shown inFIG. 43 and further proximally until the tube 1837 is withdrawn entirelyfrom the balloon 1836 and hemostasis valve with side port 1841 asillustrated in FIG. 44. Further, as shown in FIG. 44, the proximal end1861 of the balloon 1836 may be trimmed at the injection port 1831. Thetrimming process may be performed before or during the setting of theresin. The balloon 1836 and braid 1805 may be fabricated from resorbablematerials.

As illustrated in FIGS. 45-54, the components of the assembly 1835 canbe varied. For example, the balloon 1836 may be replaced with the bag orsleeve or other suitable enclosure for retaining resin in the IM canal.The elongated braided structure 1805 may be replaced with a triaxialbraid 1815, a spacer fabric structure 1810, or one of the structuresshown in FIGS. 49-54. The balloon 1836, bag or sleeve may be eliminatedentirely if the combination of the braid or spacer fabric and resinprovides the desired amount of resin retention. Chopped fibers may alsobe inserted into either the balloon 1836 (or bag or sleeve), braid 1805or spacer fabric to strengthen the resin and/or the composite structure.If chopped fibers are utilized, an elongated braid or spacer fabric maynot be necessary and a balloon, bag or sleeve structure containing asuitable amount of fibers can be inserted into the IM canal and filledwith resin. Reinforcing elements in the form of pins or tubes may alsobe employed. If a reinforcing element is utilized, a braided sleeve orspacer fabric may be utilized, pre-wetted with resin, the excess resinremoved and the braid or spacer fabric inserted into the IM canal usingthe reinforcing element. In such an embodiment, the resin may be lightcurable and a light pipe or light device may be inserted downwardthrough the braid or spacer fabric for curing the resin as shown in FIG.48 and discussed below.

FIGS. 45-48 are cross-sectional views of various insertion assemblies1835 a-1835 d. These cross-sectional views are not the scale and areintended to describe the various combination of elements for insertionassemblies that are encompassed by this disclosure.

FIG. 45 is a cross-sectional view of an assembly 1835 a that comprisesan insertion tube 1850, a balloon 1836 (or bag or sleeve) and anelongated braid 1805 (or triaxial braid 1815 or spacer fabric structure1810). The elongated braided structure 1805 is filled with resin 1870using an injection tube 1837 (not shown in FIG. 45). Optionally, theelongated braided structure 1805 may have been partially filled orcharged with chopped fibers 1871 for added strength to the compositestructure once the resin 1870 has cured. It is anticipated that theelongated braided structure 1805 may be chosen so as to preventmigration of resin 1870 to the annular area 1872 between the elongatedbraided structure 1805 and the balloon 1836. If this is the case, theballoon 1836 (or bag or sleeve) may not be necessary. If substantialmigration occurs to the area 1872, a retention means such as a balloon1836 or bag or sleeve may be desirable to prevent resin migration toother parts of the patient's body. The elongated braid 1805 and balloon1836 are sized to expand and engage the endosteal wall of the IM canal.The expansion may be natural for the elongated braided structure 1805 asit expands to its relaxed state or the expansion may be prompted orcaused by the injection with the resin 1870.

On the other hand, turning to FIG. 46, a braid, bag or sleeve is notutilized. In the assembly 1835 b includes an insertion tube 1850 aballoon 1836 (or bag or sleeve) and an injection tube 1837 (not shown).In the assembly 1835 b, the balloon 1836 is optionally charged withchopped fibers 1871. The balloon 1836 will then be injected with resin1870 (not shown in FIG. 46) to form a composite structure of resin 1870,fibers 1871 and the balloon 1836 in the IM canal. The balloon 1836 (orbag or sleeve) is preferably fabricated from resorbable material. Asnoted above, a braid 1805 can be used that is pre-charged with choppedfibers 1871 prior to injection with resin 1870. Upon injection withresin 1870, the balloon 1836 will engage the endosteal wall of the IMcanal.

Turning to FIG. 47, the assembly 1835 c includes an insertion tube 1850,a balloon 1836 and braid 1805 and a structural stiffening member 1875.While only a single stiffening member 1875 is shown, a plurality ofstiffening members 1875 may be utilized. Further, while a tubularstiffening member 1875 is illustrated, the stiffening member may be apin or rod as well. Other shapes for stiffening members 1875 will beapparent to those skilled in the art. Resin may be injected through theaxial opening 1876 in the stiffening member 1875 or through the annulararea 1877 between the elongated braided structure 1805 and stiffeningmember 1875 using an injection tube 1837 (not shown in FIG. 47). Again,the balloon 1836 (or bag or sleeve) may not be necessary, depending uponthe structure of the elongated braided structure 1805 and its ability toretain and prevent migration of resin. Alternatively, the elongatedbraided structure 1805 (or spacer fabric structure 1810) may beeliminated in favor of the balloon 1836, bag or sleeve. Again, theelongated braid 1805 or spacer fabric structure 1810 and balloon 1836,if utilized, are sized so as to expand engage the endosteal wall of theIM canal.

Turning to FIG. 48, the assembly 1835 d includes an insertion tube 1850and a braid 1805 that has been pre-wetted with uncured resin 1870 a. Alight pipe or light emitting device 1880 is shown passing through theaxial center of the pre-wetted braid 1805. The elongated braidedstructure 1805 may be wetted with resin 1870 a outside of the tube 1850and the resin 1870 a may be a light-curable resin. In this embodiment,an outer balloon 1836 or retention means may not be required. Once theinsertion tube 1850 is removed, the elongated braided structure 1805 isallowed to expand and engage the endosteal wall of the IM canal beforethe resin is cured with the light-emitting device 1880.

In addition to a single elongated braid 1805, for added structuralstrength, a plurality of braids or braids with multiple cavities thatextend along the length of the braid and may be employed as illustratedin FIGS. 49-54. FIG. 49 illustrates the use of a smaller elongated braid1805 a disposed axially within a larger braid 1805 b. FIG. 50illustrates a plurality of smaller braids 1805 c used as a bundle 1890.FIG. 51 illustrates the use of a bundle 1890 as shown in FIG. 50disposed within a larger outer braid 1805 b. The multiple braid systemsof FIGS. 49-50 provide additional braided surface areas that becomeembedded or filled with resin 1870. When the resin is cured, thestructures shown in FIGS. 49-51 will typically be stronger than singlebraid systems.

In contrast, the elongated braided structures may include multiplecavities as illustrated in FIGS. 52-54. In FIG. 52, the elongatedbraided structure 1805 d includes a pair of perpendicular wallstructures 1891, 1892 to create for cavities 1893 that extend along thelength of the elongated braided structure 1805 d. In FIG. 53, theelongated braided structure 1805 e includes three walls 1894 to createthree cavities 1893. In FIG. 54, the braid structure 1805 f includes anouter elongated braid 1805 g, an inner elongated braid 1805 h, and aplurality of radial wall structures 1895 that define a plurality ofperipheral cavities 1893 b that extend along the length of the braidstructure 1805 f. The wall structures 1891-1895 become filled orembedded with resin 1870 to add strength to the overall braid structures1805 d-1805 f.

In summary, a vast number of possibilities for the insertion assembly1835, 1835 a-1835 d is possible. Elongated braided structures 1805 ortriaxial braided elongated structures 1815 may be used alone with resin1870 or in combination with a retention means such as a balloon 1836,bag or sleeve. Spacer fabric structures 1810 may be used alone withresin or in combination with a retention means such as a balloon 1836,bag or sleeve. Chopped fibers 1871 may be added to the resin in any ofthe above embodiments or added to the elongated braided structure 1805or spacer fabric structure 1810 prior to insertion and prior toinjection with resin 1870. A balloon 1836, bag or sleeve may be chargedwith chopped fibers and used with or without an elongated braid 1805,triaxial braid 1815, or spacer fabric structure 1810, 1810 a. Resorbablereinforcing elements such as pins or tubes 1875 may be combined with anyof the above embodiments. Elongated braid structures 1805, elongatedtriaxial braided structures 1815 and spacer fabric structures 1810 mayalso be pre-wetted with resin prior to insertion and then cured in situafter radial expansion to the endosteal wall. The reinforcing elementmay be used to insert the pre-wetted braid 1805, 1815 or the spacerfabric structure 1810. In addition to single braid systems illustratedin FIGS. 36-48, multiple braid systems or braids with multiple cavitiesmay be utilized as illustrated in FIGS. 49-54 to provide additionalbraided surface areas that can be embedded with cured resin for addedstrength. Any of the braided structures illustrated in FIGS. 49-54 maybe triaxial, or braided structures with longitudinal fibers orlongitudinal fiber bundles disposed therein.

An elongated braid 1805, 1815 or spacer fabric structure 1810 ismanufactured as described above. The distal end 1830 of the elongatedbraided structure 1805 may be tapered or shaped as described above. Inany event, the ends of the elongated braided structure 1805, 1815 or thespacer fabric structure 1810 should be melted to eliminate fraying. Inone example, the flexible insertion tube 1850 has an OD of about 4.2 mmand the elongated braid 1805 has a relaxed OD of about 8 mm. Theelongated braided structure 1805 is placed over the flexible injectiontube 1837 which, at its distal end, has an OD of about 2 mm. Theinjection tube 1837 is used to push the elongated braided structure 1805into the insertion tube 1850 or, if a balloon 1836, bag or sleeve isemployed, the injection tube 1837 is used to push the elongated braidedstructure 1805 into the balloon 1836 and then the injection tube 1837,braid 1805, and balloon 1836 are then inserted into the flexibleinsertion tube 1850. The distal end of the balloon 1836 is closed andthe proximal end of the balloon 1836 may include a valve such as ahemostatic valve to provide a seal around the injection tube 1837.

Surgical kits of various forms may also be provided for use byphysicians. For example, a surgical kit may include a woven elongatedstructure 1805, which accommodates a distal end of an injection tube1837, and which is disposed within a balloon 1836. The balloon 1836,elongated woven structure 1805 and injection tube 1837 may be disposedwithin an insertion tube or catheter 1850. A valve 1841 may are may notbe connected to the balloon 1836 and injection tube 1837. A syringe orother resin 1870 delivery device may also be included for deliveringresin 1870 to the woven elongated structure 1805 and to the interior ofthe balloon 1836. The resin 1870 may also be provided in a kit formwhich includes an appropriate catalyst and filler, if necessary.Reinforcing elements 1875 or fibers 1871 may also be included and may bepositioned inside the woven elongated structure 1805.

Surgical Procedures

Various surgical procedures may be employed to utilize the assemblies1835-1835 d. First, an incision is made in an entry portal 1831 isdrilled into the fractured bone at an appropriate spacing from thefracture 102. The two-part polyurethane resin is mixed. The selectedassembly 1835-1835 d is then inserted into the IM canal. The insertiontube 1850 is withdrawn. The resin is injected through the injection tube1837 thereby filling the elongated braided structure 1805 (or braid 1815or spacer fabric structure 1810) and balloon 1836 (or bag or sleeve)with resin 1870. The injection tube 1837 is withdrawn and the proximalend of the balloon 1836 is trimmed at the portal site 1831. The incisionis then closed. The elongated braided structure 1805 and/or balloon 1836may be pre-charged with chopped fibers 1871 as described above. Aballoon 1836 (or bag or sleeve) may be utilized without a braid 1805 andvice versa as discussed above.

If a pre-wetted braid 1805 is utilized, an incision and entry portal1831 is made. The resin 1870 is mixed and injected into a container. Theelongated braid 1805, triaxial elongated braid 1815 or spacer fabricstructure 1810 is soaked in the resin and then inserted into the IMcanal using an insertion tube 1850 and injection tube 1837 as a pusher.The insertion tube 1850 is withdrawn. If the resin is to be cured bybody temperature, the injection tube 1837 can be withdrawn. If light isneeded to cure the resin 1870, a light pipe or other light emittingdevice is inserted down through the wetted braid 1805, 1815 or spacerfabric structure 1810. The light is passed through the wetted fabric andthen withdrawn. The wound is then closed. A pre-wetted braid 1805, 1815or spacer fabric structure 1810 can also be practiced with a balloon1836, bag or sleeve, with or without light-curable resin.

The structures and methods disclosed herein may be used independentlyfor bone treatment or fracture repair. Alternatively, the structures andmethods disclosed herein may be used in conjunction with external orinternal devices. The structures and methods disclosed herein also maybe used in an osteotomy.

While only certain embodiments have been set forth, alternatives andmodifications will be apparent from the above description to thoseskilled in the art. These and other alternatives are consideredequivalents and within the spirit and scope of this disclosure and theappended claims.

The invention claimed is:
 1. A hardenable and moldable material fororthopedic implantation and reconstruction, the material comprising: aresorbable polymer resin; a first filler having a first mean particlediameter ranging from about 5 to about 15 μm; and at least oneadditional filler selected from the group consisting of a second fillerhaving a mean particle diameter ranging from about 400 to about 1800 μmand a third filler having a mean particle size ranging from about 1800to about 4000 μm, wherein the at least one additional filler providesporosity within the material after hardening and is present in an amountgreater than the first filler.
 2. The material of claim 1 wherein: theresin is present in an amount ranging from about 15 to about 40 wt %;the first filler is present in an amount ranging from about 10 to about25 wt %; the additional filler is present in an amount greater than thefirst filler and ranging from about 20 to about 75 wt %.
 3. The materialof claim 2 wherein the additional filler comprises both second and thirdfillers.
 4. The material of claim 3 wherein the first filler has a meanparticle diameter ranging from about 8 to about 12 μm, the second fillerhas a mean particle diameter ranging from about 800 to about 1800 μm andthe third filler has a mean particle diameter ranging from greater than1800 to about 2800 μm.
 5. The material of claim 4 wherein: the resin ispresent in an amount ranging from about 20 to about 30 wt %; the firstfiller is present in an amount ranging from about 10 to about 20 wt %;the second filler is present in an amount ranging from about 25 to about35 wt %; the third filler is present in an amount ranging from about 20to about 30 wt %.
 6. The material of claim 4 wherein the resin ispresent in an amount ranging from about 15 to about 40 wt %; the firstfiller is present in an amount ranging from about 10 to about 25 wt %;the second filler is present in an amount ranging from about 20 to about40 wt %; the third filler is present in an amount ranging from about 15to about 35 wt %.
 7. The material of claim 6 wherein the first filler ispresent in a first amount, the second filler is present and a secondamount and the third filler is present in a third amount, and a ratio ofthe second to third amounts ranges from about 1:1 to about 1.5:1.
 8. Thematerial of claim 7 wherein a ratio of the second and third amountscombined to the first amount ranges from about 3.5:1 to about 4.5:1. 9.The material of claim 1 further comprising a porogen comprising watersoluble crystals.
 10. The material of claim 9 wherein the porogencomprises mannitol.
 11. The material of claim 1 further comprising wateras a blowing agent.
 12. The material of claim 1 wherein the first, andadditional fillers are selected from the group consisting of degradablepolymer PU, PLA, PGA, PCL, or co-polymers thereof, hydroxyapatite (HA),calcium phosphates, orthophosphates, monocalcium phosphates, dicalciumphosphates, tricalcium phsosphates, whitlockite, tetracalciumphosphates, amorphous calcium phosphates, magnesium and magnesiumalloys.
 13. The material of claim 12 comprising at least two differentfillers from the group.
 14. The material of claim 12 wherein the firstfiller is hydroxyapatite (HA) having a mean particle diameter of 10 μm.15. The material of claim 1 comprising at least two different materialsselected from the group consisting of degradable polymers PU, PLA, PGA,PCL, or co-polymers thereof, hydroxyapatite (HA), calcium phosphates,orthophosphates, monocalcium phosphates, dicalcium phosphates,tricalcium phosphates, whitlockite, tetracalcium phosphates andamorphous calcium phosphates, magnesium, magnesium alloys and calciumsulfate.
 16. The material of claim 1, wherein upon combination with theresorbable polymer resin, the at least one additional filler createsvoids that increase the porosity of the material.
 17. A kit for anorthopedic implant comprising: a resorbable polymer resin; a firstfiller having a mean particle diameter ranging from about 5 to about 15μm; and at least one additional filler selected from a second fillerhaving a mean particle diameter ranging from about 400 to about 1800 μmand a third filler having a mean particle size ranging from about 1800to about 4000 μm; wherein mixing the fillers with the resorbable polymerresin forms a hardenable and moldable putty.
 18. The kit of claim 17wherein: the resin is present in an amount ranging from about 15 toabout 40 wt %; the first filler is present in an amount ranging fromabout 10 to about 25 wt %; the additional filler is present in an amountgreater than the first filler and ranging from about 20 to about 75 wt%.
 19. The kit of claim 17 wherein the additional filler comprises bothsecond and third fillers.
 20. The kit of claim 17 wherein the firstfiller is present in a first amount, the second filler is present and asecond amount and the third filler is present in a third amount, and aratio of the second to third amounts ranges from about 1:1 to about1.5:1.
 21. A hardenable and moldable material for orthopedicimplantation and reconstruction, the material comprising: a resorbablepolymer resin; at least one filler selected from the group consisting offirst filler particles having a mean particle diameter ranging fromabout 400 to about 1800 μm and second filler particles having a meanparticle size ranging from about 1800 to about 4000 μm, wherein thefiller provides porosity within the material after hardening; and anadditional filler comprising particles having a mean particle diameterof about 5 μm to about 15 μm.
 22. The material of claim 21 wherein thefirst filler particles are present in a first amount and the secondfiller particles are present in a second amount, and a ratio of thefirst to second amounts ranges from about 1:1 to about 1.5:1.
 23. Thematerial of claim 21 wherein the at least one filler comprises thesecond filler particles having a mean particle diameter of about 1800 μmto about 4000 μm.